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Conceptual Data Model
User’s Guide

Sybase® PowerDesigner®
12.0
Windows

Part number: DC38084-01-1200-01
Last modified: December 2005
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Contents
About This Manual
1 Conceptual Data Model Basics
What is a CDM? . . . . . . . . .
Defining the CDM environment .
Defining a CDM . . . . . . . . . .
Defining packages in a CDM . .

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1
2
4
13
18

2 Using Business Rules in a CDM
What is a business rule in CDM? . . . . . . . . . . . . . . . .
Defining a business rule in a CDM . . . . . . . . . . . . . . .
Working with business rules in a CDM . . . . . . . . . . . . .

21
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23
27

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3 Building Conceptual Data Models
Defining data items in a CDM . . . .
Defining domains in a CDM . . . . .
Defining entities in a CDM . . . . . .
Defining entity attributes in a CDM .
Defining identifiers in a CDM . . . .
Defining relationships in a CDM . . .
Defining associations in a CDM . . .
Defining inheritances in a CDM . . .
Defining check parameters in a CDM

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29
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. 52
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. 69
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. 95
. 110
. 123

4 Working with Conceptual Data Models
129
Checking a CDM . . . . . . . . . . . . . . . . . . . . . . . . . 130
Object parameters verified by Check model . . . . . . . . . . 136
Opening a PAM into a CDM . . . . . . . . . . . . . . . . . . . 151
5 Generating from a Conceptual Data Model
Generation basics . . . . . . . . . . . . . . . . . . . . . . . .
Generating a Conceptual Data Model from a Conceptual
Data Model . . . . . . . . . . . . . . . . . . . . . . . . .
Generating a Physical Data Model from a Conceptual Data
Model . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Generating an Object Oriented Model from a Conceptual
Data Model . . . . . . . . . . . . . . . . . . . . . . . . .

153
154

6 CDM Glossary

177

155
157
171

iii

Index

179

About This Manual
Subject
This book describes the PowerDesigner Conceptual Data Model data
modeling environment. It shows you how to do the following:
♦ Build a Conceptual Data Model (CDM)
♦ Create and use business rules and other model objects
♦ Verify the model and import an ERwin model
♦ Generate other models from the CDM
Audience
This book is for anyone who will be building data models with the
PowerDesigner Conceptual Data Model. Although it does not assume you
have knowledge about any particular topic, having some familiarity with
relational databases, SQL, and design methodology is helpful. For more
information, see the Bibliography section at the end of this chapter.
Documentation primer
The PowerDesigner modeling environment supports several types of models:
♦ Conceptual Data Model (CDM) to model the overall logical structure of
a database, independent from any software or data storage structure
considerations
♦ Physical Data Model (PDM) to model the overall physical structure of a
database, taking into account DBMS software or data storage structure
considerations
♦ Object Oriented Model (OOM) to model a software system using an
object-oriented approach for Java or other object languages
♦ Business Process Model (BPM) to model the means by which one or
more processes are accomplished in operating business practices
♦ XML Model (XSM) to model the structure of an XML file using a DTD
or an XML schema
♦ Requirements Model (RQM) to list and document the customer needs
that must be satisfied during a development process
v

♦ Information Liquidity Model (ILM) to model the replication of
information from a source database to one or several remote databases
using replication engines
♦ Free Model (FEM) to create any kind of chart diagram, in a context-free
environment
This book only explains the Conceptual Data Model. For information on
other models or aspects of PowerDesigner, consult the following books:
To get familiar with the PowerDesigner interface
before learning how to use any of the models.
General Features Guide

Physical Data Model User’s Guide

To work with the PDM.

Object Oriented Model User’s Guide

To work with the OOM.

Business Process Model User’s Guide
XML Model User’s Guide

To work with the BPM.

To work with an XSM.

Information Liquidity Model User’s Guide
Requirements Model User’s Guide
Reports User’s Guide

To work with an ILM.

To work with an RQM.

To create reports for any or all models.

Repository User’s Guide

To work in a multi-user environment using a

central repository.
Typographic conventions
PowerDesigner documentation uses specific typefaces to help you readily
identify specific items:
♦ monospace text (normal and bold)
Used for: Code samples, commands, compiled functions and files,
references to variables.
Example: declare user_defined..., the BeforeInsertTrigger
template.
♦ bold text
Any new term.
Example: A shortcut has a target object.
♦

SMALL CAPS

Any key name.
Example: Press the ENTER key.

Bibliography
Data Modeling Essentials
Graeme Simsion, Van Nostrand Reinhold, 1994, 310 pages; paperbound;
ISBN 1850328773
Information Engineering
James Martin, Prentice Hall, 1990, three volumes of 178, 497, and 625
pages respectively; clothbound, ISBN 0-13-464462-X (vol. 1),
0-13-464885-4 (vol. 2), and 0-13-465501-X (vol. 3).
Celko95
Joe Celko, Joe Celko’s SQL for Smarties (Morgan Kaufmann Publishers,
Inc., 1995), 467 pages; paperbound; ISBN 1-55860-323-9.

vii

viii

CHAPTER 1

Conceptual Data Model Basics
About this chapter
Contents

This chapter presents the Conceptual Data Model (CDM) and explains the
role of conceptual modeling in the design process.
Topic:

page

What is a CDM?

Defining the CDM environment

Defining a CDM

Defining packages in a CDM

What is a CDM?

What is a CDM?
When designing a database, the design process normally starts at the
conceptual level. At the conceptual level, you do not need to consider the
details of actual physical implementation.
A CDM represents the overall logical structure of a database, which is
independent of any software or data storage structure. A conceptual model
often contains data objects not yet implemented in the physical database. It
gives a formal representation of the data needed to run an enterprise or a
business activity.

CDM roles
The CDM allows you to:
♦ Represent the organization of data in a graphic format to create Entity
Relationship Diagrams (ERD)
♦ Verify the validity of data design
♦ Generate a Physical Data Model (PDM), which specifies the physical
implementation of the database
♦ Generate an Object-Oriented Model (OOM), which specifies an object
representation of the CDM using the UML standard
♦ Generate a Conceptual Data Model (CDM), to create another model
version in order to represent different design stages

+ For more information on ERD, see the following book Information
Engineering , James Martin, Prentice Hall, 1990, three volumes of 178, 497,
and 625 pages respectively

Logical model
The logical model allows you to design the database structure and perform
some database denormalization actions.
In PowerDesigner, you design a logical model using a PDM with the
DBMS. This PDM is a physical model with standard
objects, and without DBMS specific physical options and generation
capabilities.
In the database design process, you use a logical model as an intermediary
step between conceptual and physical design:
♦ Start with a CDM containing entities, attributes, relationships, domains,
data items and business rules
2

Chapter 1. Conceptual Data Model Basics

♦ Generate a logical model (PDM with the DBMS).
Create indexes and specify FK column names and other common features
♦ Generate a set of PDMs, each targeted to a specific DBMS
implementation
If need be, you may develop the CDM in several design steps starting from a
high level model to a low level CDM.
This design process allows you to keep everything consistent in a large
development effort.

+ For more information on the physical data model, see the PDM User’s
Guide .
Objects in a CDM
A CDM represents the interaction of the following objects:
Object

Tool

Description

Domain

—

Set of values for which a data item is valid

Data item

—

Elementary piece of information
Person, place, thing, or concept that has characteristics of interest to the enterprise and about
which you want to store information

Entity

Entity attribute

—

Elementary piece of information attached to an
entity

Identifier

—

Entity attribute, or a combination of entity attributes, whose values uniquely identify each
occurrence of the entity

Relationship

Named connection or relation between entities
(Entity Relationship (ER) modeling methodology)

Inheritance

Special relationship that defines an entity as a
special case of a more general entity

Association

Named connection or association between entities (Merise modeling methodology)

Association
link

Link that connects an association to an entity and
on which you define the cardinality an entity has
relative to another

Defining the CDM environment

Defining the CDM environment
The CDM environment includes a set of parameters and configuration
options that define various aspects of the model content and behavior. You
can set these parameters:
♦ At model creation
♦ After creating a model with default options and parameters
♦ When creating a model template

CDM options
♦ You can set the following CDM options:
♦ All Objects, see section “All objects” on page 5
♦ Notation, see section “Notation” on page 6
♦ Data item, see section “Data item” on page 9
♦ Relationship, see section “Relationship” on page 10
♦ Domain/attribute, see section “Domain and attribute” on page 10

Chapter 1. Conceptual Data Model Basics

v To define CDM options
1. Select Tools ä Model options.

or
Right-click the diagram background, and select Model Options from the
contextual menu.
The Model Options dialog box opens to the Model Settings page.

2. Select CDM options in the different groupboxes.
3. Click OK.
All objects
Name/Code case
sensitive

You can define the case sensitivity of names and codes for all objects in the
current model. When this check box is selected, it implies that you can have
two objects with identical name or code but different case in the same
namespace.
Unlike other model options, you can modify the name and code case
sensitivity during the design process. However, if you do so, make sure you
run the check model feature to verify if the model does not contain any
duplicate object.

Enable links to
requirements

Requirements are descriptions of customer needs that must be satisfied
during development processes.
You can enable links to requirements for all objects in the current model.
When this check box is selected, it implies that the Requirements tab
5

Defining the CDM environment

appears in the objects property sheet. The Requirements page allows you to
attach requirements to objects; these requirements are defined in the
Requirements models open in the workspace. Attached requirements and
Requirements models are synchronized.

+ For more information on requirements, see the Requirements Model
User’s Guide .
Notation
You can choose to use one or both of the following notation types in the
current model:

Chapter 1. Conceptual Data Model Basics

Option

Description

Entity / Relationships

Entity/relationship notation connects entities
with links representing
one of four relationships
between them. These
relationships have properties that apply to both
entities involved in the
relationship

Merise

Merise notation uses
associations instead of
relationships

E/R + Merise

Both entity/relationship
and Merise are used in
the same model

IDEF1X

Data modeling notation
for relationships and entities. In this notation,
each set of relationship
symbols describes a
combination of the optionality and cardinality
of the entity next to it

Symbols

Both types of symbols

The Entity / Relationships notation is the default notation used in this
manual.
When you change notation, all symbols in all diagrams are updated
accordingly.
IDEF1X notation

Entities display rounded rectangles when they depend on another entity
7

Defining the CDM environment

either through an inheritance link or when the relationship has the dependent
property selected.
Relationships: unlike the other notations, relationship symbols cannot be
parsed in terms of optionality and cardinality independently. Each set of
symbols describes a combination of the optionality and cardinality of the
entity next to it.
Cardinality

Representation

One - Many

One - One or Many - Many

One - One dependent displays a continuous line and
entity with rounded angles

PowerDesigner does not support the following notation:

Sub-type or inheritance symbol changes according to the Complete
property:

Chapter 1. Conceptual Data Model Basics

Complete

Symbol

Yes

Data item
You can choose to use one or both of the following data item options in the
current model:
Option

Description

Unique code

When selected, requires that data items have unique codes

Allow reuse

When selected, makes it possible to reuse one data item
as an attribute for more than one entity provided the
attributes have same name and data type and do not
belong to a primary key.
When deselected or when the attribute belongs to a
primary key, the data item cannot be reused. In this case,
if the Unique code check box is selected, a new data
item with identical name but different code is created,
otherwise a new data item with identical name and code
is created

Deleting entity attributes

When you delete an entity or entity attributes, data item options determine
whether or not the corresponding data items are also deleted.
The following rules apply to deleted entity attributes:
Data item options

Result of deleting an entity attribute

Unique Code

Deletes entity attribute

Allow Reuse

Does not delete corresponding data item

Unique Code only

Deletes entity attribute
Does not delete corresponding data item

Allow Reuse only

Deletes entity attribute
Deletes corresponding data item if it is not used by
another entity

None

Deletes entity attribute
Deletes corresponding data item

Defining the CDM environment

Relationship
You can choose to select or clear the Unique code option. When selected, it
requires that relationships have unique codes.
Domain and attribute
From the Attribute and Domain groupbox in Model Options, you can choose
to enforce non-divergence between a domain definition and the attributes
using the domain, for the following attribute properties:

Enforce non-divergence
selected

Property

Attributes in the domain cannot have divergent

Data type

Data type, length, and precision

Check

Check parameters

Rules

Business rules

Mandatory

Entity, association and inheritance attribute mandatory
property

In this mode, the selected attribute properties must be consistent with the
domain properties.
You are asked if
you want to apply domain properties to attributes attached to the domain in
the current model.
When you apply the Enforce non-divergence options

♦ If you accept to apply domain properties, the attribute properties are
modified in order to be consistent with domain properties. However, if
the check parameters, business rules, and mandatory value of an attribute
are more constrained than those of the domain, these properties will not
be modified. You may indeed need to define a shorter range of values in
the attribute check parameters, or set an attribute as mandatory while the
domain is not
♦ If you refuse to apply domain properties, the attribute is detached from
the domain
The properties of the
attributes attached to the domain are updated provided these properties are
selected in the Model Options dialog box.
When you modify the properties of a domain

Attributes cannot be modified When you select an attribute property
under Enforce non-divergence, each instance of that attribute property in the
lists of attributes and the property sheets of attributes appears grayed and can
not be modified.

Chapter 1. Conceptual Data Model Basics

If you want to modify an attribute property that is defined as non-divergent,
you must detach the attribute from its domain, or clear the Enforce
non-divergence check box in Model Options.
Enforce non-divergence
deselected

In this mode, it is still possible to select attribute properties under Enforce
non-divergence.
When you modify
an attribute property so that it diverges from its current domain definition,
you are asked if you want to keep the modifications and diverge from the
domain.
If you select one or more of the attribute properties

When you modify an attribute or
domain property resulting in a divergence, you are not warned, and you can
no longer cascade the change on the attribute properties.
If you do not select attribute properties

Default data type

In a CDM, you can select a Default data type to apply to domains and
attributes if no data type is selected for them.
If you modify CDM options, these options apply only to the current CDM.

+ For information on other model options, see chapter Working with
Models.

CDM extended model definitions
An extended model definition allows you to expand object definitions and
complement the generation targets and commands. Extended model
definitions are created and saved in files with the XEM extension. You can
create or attach one or several extended model definitions to a model.
Extended model definitions may contain:
♦ Extended attributes for applicable objects in order to further define their
properties
Stereotypes to define extended dependencies established between model
objects

+ For more information on extended dependencies, see “CDM extended
dependencies” on page 12.
♦ Generation targets and commands to complement the generation of an
object model, or to perform an extended generation

+ For more information on extended model definitions, see chapter
Extended Model Definitions Reference Guide in the Advanced User
Documentation.

Defining the CDM environment

CDM extended dependencies
Extended dependencies are links between CDM objects. These links help to
make object relationships clearer but are not interpreted and checked by
PowerDesigner, as they are meant to be used for documentation purposes
only.
You can complement these links by applying stereotypes. Stereotypes are
used to define extended dependencies between objects in the CDM.
You can type stereotypes directly in the Stereotype column of the object
property sheet or select a value from the dropdown listbox if you have
previously defined stereotypes in an embedded or imported extended model
definition (.XEM).

+ For more information on extended dependencies, see section Using
Extended Dependencies in chapter Using the PowerDesigner Interface in the
General Features Guide.

Chapter 1. Conceptual Data Model Basics

Defining a CDM
You can create a new CDM, or open an existing CDM.

CDM properties
The Model property sheet displays the definition of the current model. From
this property sheet you can modify the model definition.
A CDM has the following model properties:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the model

Filename

Location of the model file. This box is empty if the model has
never been saved

Author

Author of the model. You can insert a name, a space, or nothing.
If you insert a space, the Author field in the title box remains
empty.
If you intentionally leave the box empty, the Author field in the
title box displays the user name from the Version Info page of
the model property sheet

Version

Version of the model. You can use this box to display the
repository version or a user defined version of the model. This
parameter is defined in the Title page of the model display
preferences

Default
diagram

Diagram displayed by default when you open the model

v To modify CDM properties
1. Select Model ä Model Properties.

or
Right-click the diagram background, and select Properties from the
contextual menu.
13

Defining a CDM

or
If you have inserted a title box, click the Property tool and then click the
title box.
The model property sheet appears.
2. Type changes to model properties.

3. Click OK.

Creating a CDM
There are several ways to create a CDM:
♦ Create a new CDM
♦ Create a new CDM using a template
♦ Create a new CDM using existing elements (importing one or more
CDMs, importing a ProcessAnalyst Model (.PAM) or an ERwin model
(.ERX) or generating from a PDM or OOM, etc.)
Creating a CDM using the New model option

Chapter 1. Conceptual Data Model Basics

v To create a new CDM using the New model option
1. Select File ä New to display the New dialog box.
2. Select Conceptual Data Model in the list of model types.
3. Select the New model radio button in the upper right part of the dialog
box.
4. Type a model name in the Model name box. The code of the model,
which may be used for script or code generation, is derived from this
name according to the model naming conventions.
5. Click OK.
A new CDM is created in the Workspace.
6. Select Model ä Model Properties.
The model property sheet appears.
7. Modify the name and code of the model.

8. Click OK.
Demo example

An example of a CDM is available in the Examples directory.

Defining a CDM

Creating a CDM using the New model from template option
v To create a new CDM using the New model from template option
1. Select File ä New to display the New dialog box.
2. Select Conceptual Data Model in the list of model types.
3. Select the New model from template radio button in the upper right part
of the dialog box.
4. Select a model template from the list.
List of templates

You can select user-defined model templates (use the Change UserDefined Model Templates Folder tool to specify the user templates
folder) and copy some existing models as model templates using the
Copy Model to User-Defined Model Templates Folder tool.

+ For more information on model templates, see section Creating a
model in chapter Managing Models, in the General Features Guide.
5. Click OK.
A new CDM is created in the Workspace.
6. Select Model ä Model Properties.
The model property sheet appears.
7. Type a model name and code.
8. Click OK.
Demo example

An example of an CDM is available in the Examples directory.

Opening an existing CDM
A Conceptual Data Model has the file extension .CDM.
v To open an existing CDM
1. Select File ä Open to display a standard open file dialog box.
2. Select a file with the .CDM extension.

Chapter 1. Conceptual Data Model Basics

3. Click Open.
The model appears in the Browser and the diagram opens in the diagram
window.

Detaching a CDM from the workspace
You can detach a CDM from a workspace. When a CDM is detached from a
Workspace its node is removed from the Browser and it is no longer defined
in the workspace, but the file is not deleted from your operating environment.
v To detach a CDM from a workspace
1. Right-click the CDM node in the Browser and select Detach From
Workspace from the contextual menu.
A confirmation box asks if you want to save the CDM.
2. Click Yes if you want to save modifications to the CDM.
Select or browse to a directory.
Type a name for the file and click the Save button.

or
Click No if you do not want to save modifications to the file.
The CDM is removed from the workspace.

Saving and closing a CDM
You save a CDM by selecting File ä Save.
You close a CDM by selecting File ä Close.

Defining packages in a CDM

Defining packages in a CDM
A package is a piece of a model.

+ When working with a large model, you can split the model into smaller
subdivisions to avoid manipulating the entire set of model objects. Packages
can be useful to assign portions of a model, representing different tasks and
subject areas, to different development teams.

Package hierarchy

You can create several packages at the same hierarchical level within a
model or decompose a package into other packages and continue this
process without limitation in decomposition depth. Each package appears
with a default diagram window. At each level of decomposition you can
create several diagrams.

+ For more information on packages, see the General Features Guide .
Composite view

You can expand a package to have a global view of the whole diagram
content.
To do so, you have to right-click a package and select Composite View from
the contextual menu. You must resize the composite package symbol to
visualize its content:

To return to the package normal view, re-select the Composite View
command in the contextual menu of the expanded package.
Note that if you double-click the composite view, you automatically open
the sub-package diagram.
18

Chapter 1. Conceptual Data Model Basics

+ For more information on the composite view feature, see section
Expanding the symbol of a composite object in chapter Model Graphics in
the General Features Guide.

CDM package properties
Packages have properties displayed on property sheets. All packages share
the following common properties:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Optional label that describes a package and provides additional
information

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Default diagram

Diagram displayed by default when you open the package

Use Parent
Namespace

Defines the package as being the area in which the name of an
object must be unique in order to be used.

Creating a CDM package
A package always belongs to a model. You create a package like any other
model objects.
The name of each package must be unique in the model.
There are several ways to create a package:
♦ From a diagram
♦ From the Browser
♦ From the list of packages
At creation, a package has a default name including a number, this number is
assigned in the order of creation.

Defining packages in a CDM

+ For more information on the different ways to create a package, see
section Creating an object in chapter managing Objects.

Modifying package display preference
You can modify the following display preference for packages using the
Tools ä Display Preferences command:

Preference

Description

Stereotype

Displays the stereotype of the package

CHAPTER 2

Using Business Rules in a CDM
About this chapter
Contents

This chapter describes how business rules help you model information.
Topic:

page

What is a business rule in CDM?

Defining a business rule in a CDM

Working with business rules in a CDM

What is a business rule in CDM?

What is a business rule in CDM?
A business rule is a rule that your business follows. A business rule could be
a government-imposed law, a customer requirement, or an internal guideline.
Starts as an observation

Business rules often start as simple observations, for example “customers
call toll-free numbers to place orders.” During the design process they
develop into more detailed expressions, for example what information a
customer supplies when placing an order or how much a customer can spend
based on a credit limit.

Guides modeling

Business rules guide and document the creation of a model. For example,
the rule “an employee belongs to only one division” can help you
graphically build the link between an employee and a division.

Complements graphics

Business rules complement model graphics with information that is not
easily represented graphically. For example, some rules specify physical
concerns in the form of formulas and validation rules. These technical
expressions do not have a graphical representation.

CDM to PDM generation

During generation of a Physical Data Model (PDM), or an Object-Oriented
Model (OOM), from a CDM, the business rules transfer directly into the
PDM or OOM. In the generated model, you further specify business rules to
suit physical concerns.

Chapter 2. Using Business Rules in a CDM

Defining a business rule in a CDM
You can define a business rule which can be attached to CDM objects.

Business rule properties in a CDM
A business rule definition includes the following properties:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the rule

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Type

Indicates whether the rule is a definition, a fact, a formula, or
a validation

A business rule definition also includes the following properties, each with
their respective page:
Property

Description

Expression

Presence of associated expression

Notes

Presence of associated notes

Types of business rule in an CDM
The different business rule types that you can define in a CDM are described
below:

Defining a business rule in a CDM

Rule type

Describes

Example

Definition

Properties of the element in
the information system

A customer is a person identified by a name and an address

Fact

Certainty, existence in the
information system

A client may place one or
more orders

Formula

Calculation used in the information system

The total order is the sum of
all the order line costs

Requirement

Functional specification in
the information system

The model is designed so that
total losses do not exceed 10%
of total sales

Validation

Constraint on a value in the
information system

The sum of all orders for a
client must not be greater than
that client’s allowance

Constraint

Additional check constraint
on a value. Constraint business rules are used in the
PDM, they are generated in
the database

The start date should be inferior to the end date of a
project

+ For more information on constraint type, see section Using constraint
business rules in a PDM in chapter Using Business Rules in a PDM in the
Physical Data Model User’s Guide .

Creating a business rule in a CDM
Before you create business rules, formulate your rules by asking yourself the
following questions:
♦ What business problems do I want to address?
♦ Are there any procedures that my system must respect?
♦ Do any specifications dictate the scope of my project?
♦ Do any constraints limit my options?
♦ How do I describe each of these procedures, specifications, and
constraints?
♦ How do I classify these descriptions: as definitions, facts, formulas, or
validation rules?

Chapter 2. Using Business Rules in a CDM

v To create a business rule in a CDM
1. Select Model ä Business Rules to display the List of Business Rules. It
displays the business rules defined for the model.

2. Click a blank line in the list.

or
Click the Add a Row tool.
An arrow appears at the beginning of the line.
3. Type a name and a code for the business rule.
4. Click Apply.
The creation of the new business rule is committed.
5. Click the new business rule line.
An arrow appears at the beginning of the line.
6. Click the Properties tool.

or
Double click the arrow at the beginning of the line.
The property sheet for the new business rule appears.
7. Click the General tab and select a business rule type from the Type
dropdown listbox.
8. Click OK in each of the dialog boxes.

Defining a business rule in a CDM

Attaching an expression to a business rule in a CDM
A business rule typically starts out as a description. As you develop your
model and analyze your business problem, you can complete a rule by
adding a technical expression. The syntax of expressions depends on the
target database.
Each business rule can include two types of expression:
♦ Server
♦ Client
Only the server expression can be generated to a database. You can generate
server expressions as check parameters if they are attached to tables,
domains, or columns.
A client expression is used mainly for documentation purposes. However,
you can insert both types of expression into a trigger or a stored procedure.
v To attach an expression to a business rule in a CDM
1. Select Model ä Business Rules to display the List of Business Rules.
2. Double-click the new business rule line to display the business rule
property sheet.
3. Click the Expression tab to display the Expression page.
4. Click the Server tab at the bottom of the page to define a server
expression.

or
Click the Client tab at the bottom of the page to define a client expression.
5. Type an expression in the Expression textbox.
6. Click OK in each of the dialog boxes.

Chapter 2. Using Business Rules in a CDM

Working with business rules in a CDM
You can apply a business rule to an object from its property sheet.

Applying a business rule to the current CDM object
You can choose a rule to apply to the current object from its property sheet.
v To apply a business rule to the current CDM object
1. Double-click an object in the diagram to display the object property sheet.
2. Click the Rules tab to display the Rules page showing any business rules
attached to the object.

3. Click the Add Objects tool to display a selection list of business rules.
It contains a list of all the business rules of the model, except the rules
that already belong to the object.
4. Select the business rules you want to add to the object.
5. Click OK.
The business rules are added to the object and appear in the list of
business rules for the object.

Working with business rules in a CDM

6. Click OK.
U Column in the List of business rules

When you apply a business rule to an object, the U (Used) column
beside this business rule is automatically checked in the List of business
rules to indicate that the business rule is used by at least one object in
the model. The U column allows you to visualize unused business rules,
you can then delete them if necessary.

CHAPTER 3

Building Conceptual Data Models
About this chapter

Contents

This chapter describes how to build a Conceptual Data Model (CDM). It
explains the role of each object in a conceptual model and shows how to
modify them in a conceptual diagram.
Topic:

page

Defining data items in a CDM

Defining domains in a CDM

Defining entities in a CDM

Defining entity attributes in a CDM

Defining identifiers in a CDM

Defining relationships in a CDM

Defining associations in a CDM

Defining inheritances in a CDM

110

Defining check parameters in a CDM

123

Defining data items in a CDM

Defining data items in a CDM
A data item is an elementary piece of information in a model. It represents
a fact or a definition in an information system, which may or may not have
any eventual existence as a modeled object.
You can attach a data item to an entity. It then becomes an entity attribute of
that entity. When a physical data model (PDM) is generated from a CDM,
an entity attribute generates a column in a table.
You can also define a data item, but not attach it to an entity. It remains
defined in the model and can be attached to an entity at any time.
Depending on its defined model options, a data item can be unique in the
model, or unique only for a particular entity. In the latter case, a data item is
equivalent to an entity attribute.
Example

In the information system for a publishing company, the last names for
authors and customers are both important pieces of business information.
The data item LAST NAME is created to represent this information. It is
attached to the entities AUTHOR and CUSTOMER, and becomes entity
attributes of those entities.
Another piece of information is the date of birth of each author. The data
item BIRTH DATE is created in the CDM, but as there is no immediate need
for this information in the model, it remains in the CDM, but is not attached
to any entity.

Data item properties
You can access data item properties from the list of data items. Each data
item definition includes the following general properties:

Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the data item

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Chapter 3. Building Conceptual Data Models

Property

Description

Data type

Code indicating the data format, such as N for numeric or A
for alphanumeric, followed by the number of characters

Length

Maximum number of characters

Precision

Number of places after the decimal point, for data values that
can take a decimal point

Domain

Name of the associated domain

A data item definition also includes the following properties, each with their
own respective property sheets:
Property

Description

Standard checks

Check parameters defined for the domain

Additional checks

Domain constraints or validation rules not defined by
standard check parameters

Rules

Business rules attached to the domain

Creating a data item
There are several ways to create a data item:
♦ From the list of data items
♦ From the Browser
At creation, a data item has a default name including a number. This number
is assigned in the order of creation of objects.

+ For more information on the different ways to create a data item, see
section Creating an object in chapter Managing objects in the General
Features Guide .

Defining data items in a CDM

v To create a data item from the list of data items
1. Select Model ä Data Items to display the list of data items.

2. Click a blank line in the list.

or
Click the Add a Row tool.
An arrow appears at the beginning of the line.
3. Type a data item name and a data item code.
4. (Optional) Click the Data Type column for the same row.
Display the column you need

If you do not see the column you need, display it with the Customize
Columns and Filter tool. For details, see the General Features Guide .
Click the down arrowhead and select a data type from the dropdown
listbox.

or
Click the ellipsis button to display the list of standard data types and click
the radio button corresponding to the data type you want to apply.
Type the maximum number of characters for the data item in the Length
box.
If the data type can include values that take a decimal point, type the
number of places after the decimal point in the Precision box.
Click OK.

Chapter 3. Building Conceptual Data Models

5. (Optional) Click the Domain column for the same row.
Select a domain from the dropdown listbox.
6. Click OK.

+ For more information on selecting a data type for a domain see section
“Selecting a data type for a domain in a CDM” on page 42.

+ For information on indicating data type length and precision, see section
“Indicating data type, length, and precision in a CDM” on page 42.

+ For more information on attaching a data item to a domain, see section
“Attaching a data item to a domain” on page 36.
Deleting a data item
You delete a data item from the list of data items. When you delete a data
item you also delete all entity attributes using that data item.
v To delete a data item
1. Select ä Model ä Data Items to display the list of data items.
2. Click a data item in the list.
An arrow appears at the beginning of the line.

Defining data items in a CDM

Selecting a line in a list

You can select a line in a list by clicking the number at the beginning of
the line. An arrow replaces the number and the line is selected.
3. Click the arrow at the beginning of the line.
The line is selected.
4. Click the Delete tool.

or
Press DELETE.
The data item and all entity attributes using the data item are deleted.
5. Click OK.

Copying a data item in the list
You can copy and paste a data item in the list of data items. Copying a data
item creates a new data item.
Same code for different data items

If you do not choose the Unique Code data item option, you can use the
same code for different data items as long as each of these data items is
attached to a different entity. You access data item options by selecting
Tools ä Model Options.
v To copy a data item in the list
1. Select Model ä Data Items to display the list of data items.
It lists the data items defined in the model.
2. Click the line for the data item that you want to copy.
An arrow appears at the beginning of the line.
3. Click the arrow at the beginning of the line.
The line is selected.
4. Click the Copy tool.
5. Click the Paste tool.
The data item is copied to the next line in the list. If the Unique code data
item option is selected in Model Options, the copied data item is
renamed.

Chapter 3. Building Conceptual Data Models

Defining code and reuse options for data items
You can define the following options for data items:
Option

Result when selected

Result when cleared

Unique code

Each data item has a unique
code

Different data items can
have the same code

Allow reuse

One data item can be an entity
attribute for more than one
entity

One data item can be an
entity attribute for only one
entity

If you do not select Unique Code, two data items can have the same code. In
this case, you differentiate the data items by the entities that use them. The
entities are listed in the Dependencies column of the list of data items.
Item not visible in list

To make an item visible in a list, click the Customize Columns and Filter
tool in the list toolbar, select the appropriate check box from the list of filter
options that appears, and click OK.
v To define code and reuse options for data items
1. Select Tools ä Model Options.
The Model Options dialog box opens to the Model Settings page.

Defining data items in a CDM

2. Select the Unique Code check box in the Data Item groupbox to require a
unique code for each data item.

or
Clear the Unique Code check box in the Data Item groupbox to allow
more than one data item to have the same code.
3. Select the Allow Reuse check box to allow the one data item to be an
entity attribute for more than one entity.

or
Clear the Allow Reuse check box to prohibit the one data item from
being an entity attribute for more than one entity.
4. Click OK.
Error message

The following error message appear when you select the Unique Code, when
it is incompatible with the current CDM:
Error message

Solution

Unique Code option could not be
selected because two data items have
the same code: data_item_code.

Assign unique codes to all data
items

Attaching a data item to a domain
If you attach a data item to a domain, the domain supplies the data type and
related data characteristics.
The domain applies a standard data type to the data item. It can also apply
length, decimal precision, and check parameters.
v To attach a data item to a domain
1. Select Model ä Data Items to display the list of data items.
2. Click the data item to define.
An arrow appears at the beginning of the line.
3. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The data item property sheet opens to the General page.

Chapter 3. Building Conceptual Data Models

Opening property sheets at last accessed page

You can choose to open property sheets at the last accessed page by
selecting Tools ä General Options ä Dialog, and selecting the option
Keep Last Tab in the Property Sheets groupbox.
4. Select a domain from the Domain dropdown listbox at the bottom of the
dialog box and click OK.

or
Click the Ellipsis button at the end of the Domain dropdown listbox.
Select a domain from the list that appears and click OK.
You return to the list of data items. In the Data Type column, the data type
for the domain replaces the data type previously defined for the data item.
5. Click OK.

Selecting a data type for a data item
There are two ways to select a data type for a data item.
♦ Attach the data item to a domain
The domain dictates a standard
data type, a length, and a level of precision, as well as optional check
parameters
♦ Manually select a data type
You select a standard data type along
with a length, a level of precision, and optional check parameters
37

Defining data items in a CDM

+ For more information on attaching a data item to a domain, see
section “Attaching a data item to a domain” on page 36.
About check parameters

Check parameters indicate data ranges and validation rules. You can attach
check parameters to entity attributes, data items, or domains.
v To select a data type for a data item
1. Select Model ä Data Items to display the list of data items.
2. Click the data item to define.
An arrow appears at the beginning of the line.
3. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The data item property sheet opens to the General page.

4. Select a data type from the Data Type dropdown listbox.

or
Click the Question mark button at the end of the Data Type dropdown
listbox.

Chapter 3. Building Conceptual Data Models

A list of standard data types appears.
Select the radio button corresponding to the data type you want to apply.
Click OK.
Undefined data type

If you do not want to select a data type immediately, you can choose the
data type.
5. Type the maximum number of characters for the data type in the Length
box.
6. If the data type can include values that take a decimal point, type the
number of places after the decimal point in the Precision box.
7. Click OK.
The new data type appears in the list of data items.

Configuring the display of the list of data items
You can sort the data items in the list:
♦ By any property that appears in the column header in the lists
♦ Alphabetical or reverse alphabetical order
The listed order is indicated by an arrowhead that appears in the property
column header. Each time you click a column header, you change the listed
order for that column, according to the displayed arrow.
Each arrow type corresponds to the following list orders:
Arrow type

Listed order

Down arrow

Alphabetically

Up arrow

Reverse alphabetically

For example, when you click the column header Name, the data items are
listed by name alphabetically when the Down arrow is indicated, and in
reverse order when the Up arrow is indicated.
v To configure the display of the list of data items
1. Select Model ä Data Items to display the list of data items.
2. Click a property title bar.
The listed columns are ordered by the indicated property.
3. Click OK.
39

Defining domains in a CDM

Defining domains in a CDM
Domains help you identify the types of information in your model. Applying
domains to data items makes it easier to standardize data characteristics for
entity attributes in different entities.
In a CDM, you can associate the following information with the domain:
♦ Data type, length, and precision
♦ Check parameters
♦ Business rules
♦ Mandatory

Domain properties in a CDM
You can access domain properties from the list of domains.
Each domain definition includes the following general properties:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the domain

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Data type

Form of the data corresponding to the domain, such as
numeric, alphanumeric, boolean, or others

Length

Maximum number of characters

Precision

Number of places after the decimal point, for data values that
can take a decimal point

Mandatory

Domain values are mandatory for all entity attributes using
that domain

A domain definition can also include the following properties, which have
40

Chapter 3. Building Conceptual Data Models

associated values or information used by entity attributes using the domain:
Property

Description

Standard checks

Check parameters defined for the domain

Additional checks

Domain constraints or validation rules not defined by
standard check parameters

Rules

Business rules attached to the domain

Creating a domain in a CDM
There are several ways to create a domain:
♦ From the list of domains
♦ From the Browser
At creation, a domain has a default name including a number. This number
is assigned in the order of creation of objects.

+ For more information on the different ways to create a domain, see
section Creating an object in chapter Managing objects in the General
Features Guide .
v To create a domain in a CDM from the list of domain
1. Select Model ä Domains to display the list of domains.

2. Click a blank line in the list.

or
Click the Add a Row tool.
41

Defining domains in a CDM

An arrow appears at the beginning of the line.
3. Type a domain name and a domain code.
4. Click Apply.
5. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
6. Select a data type from the dropdown listbox.
7. Specify length and precision as required.
8. Click OK in each of the dialog boxes.

Indicating data type, length, and precision in a CDM
Length and precision

The properties length and precision do not apply to all data types.
Depending on data type, length may indicate a maximum or a fixed number
of characters.
In the list of available data types, a variable indicates where you have to type
a length or precision, as follows:
Variable

Replace with

Length

Length with precision

Decimal precision

For example, if you are using Sybase Adaptive Server Anywhere and you
choose the data type char(%n), you can choose a length of ten by typing
char(10).
Undefined data type

All target DBMS allow you to select the data type. The
data type indicates which domains remain without data types.
If an data type is present when you generate your database, it
is replaced by the default data type for your database.

Selecting a data type for a domain in a CDM
You can select a data type for a domain in two ways:
♦ From the list of domains
♦ From the domain property sheet
42

Chapter 3. Building Conceptual Data Models

The list of standard data
types

When you select a data type for a domain from its property sheet, you can
choose from a list of standard data types. This list presents the available data
types in full details instead of the abbreviated format used in the data type
dropdown listbox in the list of domains.

Selecting a data type for a CDM domain from the list
v To select a data type for a CDM domain from the list
1. Select Model ä Domains to display the list of domains.
2. Click the domain to define.
An arrow appears at the beginning of the line.
3. Click the Data Type column.
4. Select a data type from the Data Type dropdown listbox.
Defining a data type later

If you do not want to select a data type immediately, you can choose the
data type.
5. Click OK.
The data type appears in the Data Type column of the list of domains.
Selecting a data type for a CDM domain from its property sheet
v To select a data type for a CDM domain from its property sheet
1. Select Model ä Domains to display the list of domains.
2. Click the domain to define.
An arrow appears at the beginning of the line.
3. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The domain property sheet appears.
4. Select a data type from the Data Type dropdown listbox.
Selecting a data type from a list of standard data types

To select a data type from a list of standard data types, click the Question
Mark button at the end of the Data Type dropdown listbox, and select
the radio button for a data type from the list that appears.
43

Defining domains in a CDM

5. Type the maximum number of characters for the data item in the Length
box.
6. If the data type can include values that take a decimal point, type the
number of places after the decimal point in the Precision box.
7. Click OK.
The change of data type appears in the list of domains.
Undefined data type

If you do not want to select a data type immediately, you can choose the
data type.

Selecting a data type from a list of standard data types in a CDM
You can select a data type from a list of standard data types. This is the same
list that is available in the Physical Data Model. PowerDesigner
automatically maps the standard data type to a conceptual data type.
The length and precision are properties that do not apply to all data types.
Furthermore, depending on data type, length may indicate a maximum or a
fixed number of characters.
The tables below indicates the data types for which you can specify:
♦ Fixed length
♦ Maximum length
♦ Decimal precision
Numeric data types

Conceptual data
type

Physical data type
(depending on the
DBMS)

Content

Length

Integer

int / INTEGER

32-bit integer

—

Short Integer

smallint / SMALLINT

16-bit integer

—

Long Integer

int / INTEGER

32-bit integer

—

Byte

tinyint / SMALLINT

256 values

—

Number

numeric / NUMBER

Numbers with
a fixed decimal point

Fixed

Chapter 3. Building Conceptual Data Models

Conceptual data
type

Physical data type
(depending on the
DBMS)

Content

Length

Decimal

decimal / NUMBER

Numbers with
a fixed decimal point

Fixed

Float

float / FLOAT

32-bit floating
point numbers

Fixed

Short Float

real / FLOAT

Less than 32bit point decimal number

♦ —

Long Float

double precision /
BINARY DOUBLE

64-bit floating
point numbers

—

Money

money / NUMBER

Numbers with
a fixed decimal point

Fixed

Serial

numeric / NUMBER

Automatically
incremented
numbers

Fixed

Boolean

bit / SMALLINT

Two opposing values
(true/false;
yes/no; 1/0)

—

Character data types

Defining domains in a CDM

Conceptual data
type

Physical data
type (depending on the
DBMS)

Content

Length

Characters

char / CHAR

Character strings

Fixed

Variable Characters

varchar / VARCHAR2

Character strings

Maximum

Long Characters

varchar /
CLOB

Character strings

Maximum

Long Var Characters

text / CLOB

Character strings

Maximum

Text

text / CLOB

Character strings

Maximum

Multibyte

nchar /
NCHAR

Multibyte character
strings

Fixed

Variable Multibyte

nvarchar /
NVARCHAR2

Multibyte character
strings

Maximum

Time data types
Conceptual data type

Physical data type
(depending on the

Content

DBMS)

Other data types

Date

date / DATE

Day, month, year

Time

time / DATE

Hour, minute, and second

Date & Time

datetime / DATE

Date and time

Timestamp

timestamp / TIMESTAMP

System date and time

Chapter 3. Building Conceptual Data Models

Conceptual data
type

Physical data
type (depending on the
DBMS)

Content

Length

Binary

binary / RAW

Binary strings

Maximum

Long Binary

image / BLOB

Binary strings

Maximum

Bitmap

image / BLOB

Images in bitmap
format (BMP)

Maximum

Image

image / BLOB

Images

Maximum

OLE

image / BLOB

OLE links

Maximum

Other

—

User-defined data
type

—

Undefined

undefined

Not yet defined data
type

—

v To select a data type from a list of standard data types in a CDM
1. Select Model ä Domains to display the list of domains.
2. Click the domain to define and display an arrow at the beginning of the
line.
3. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The domain property sheet appears.
4. Click the Question Mark button next to the Data Type dropdown listbox.
Selecting from the Data Type dropdown listbox

You can also select a data type directly from the Data Type dropdown
listbox.
A list of standard data types appears.

Defining domains in a CDM

5. Click the radio button corresponding to the data type you want to apply.
The code for the data type appears in the Code box.
Undefined data type

If you do not want to select a data type immediately, you can choose the
Undefined data type.
6. Type the maximum number of characters for the data type in the Length
box.
7. If the data type includes values after a decimal point, type the number of
places after the decimal point in the Precision box.
8. Click OK.
The change of data type appears in the Data Type box.

Modifying domain properties in a CDM
You can modify domain properties from the domain property sheet.
When you modify domain properties, a confirmation box appears asking if
you want to modify the data items and attributes currently using the domain.

Chapter 3. Building Conceptual Data Models

The Data Type check box is automatically selected and available for an
update, depending on the options set to enforce non-divergence from a
domain.
For information on domain divergence, see section “Enforcing
non-divergence from domains in a CDM” on page 50.
You can also select other properties (Check, Rules) that will be updated in
their use of the domain.
You can now click one of the following buttons with the following effects:
Button

Effect

Yes

The data items currently using the domain are modified
according to the update

The data items currently using the domain are not modified
according to the update but the current modification is accepted
if domain divergence is allowed in the model options

Cancel

The update is cancelled and nothing is changed

v To modify domain properties in a CDM
1. Select Model ä Domains to display the list of domains.
2. Click a domain from the list.
An arrow appears at the beginning of the line.
3. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The Domain property sheet appears.

Defining domains in a CDM

4. Type changes to domain properties.

or
Click on a page tab.
Type or select domain properties as required.
5. Click OK.
If the domain is used by one or more data items, an update confirmation
box appears asking if you want to modify domain properties for the data
items using the domain.
6. Select the properties that you want to update for all data items using the
domain.
7. Click Yes.

Enforcing non-divergence from domains in a CDM
From the Model Options dialog box, you can choose to enforce
non-divergence between a domain and the data items and attributes that use
the domain.

+ For more information on non-divergence enforcement, see section
Defining CDM Options in chapter Conceptual Data Model Basics.

Chapter 3. Building Conceptual Data Models

v To enforce domain non-divergence in a CDM
1. Select Tools ä Model Options.

or
Right click the diagram background.
Select Model Options from the contextual menu.
The Model Options dialog box opens to the Model Settings page.

2. Select the Enforce non-divergence check box in the Domain/Attribute
groupbox.
3. Select check boxes for the entity attribute properties that are not
permitted to diverge from the domain definition.
4. Click OK.

Defining entities in a CDM

Defining entities in a CDM
An entity represents an object defined within the information system about
which you want to store information. For example, in a model concerning
employees and divisions, the entities are Employee and Division.
An occurrence of an entity is an individual element belonging to the entity.
For example, the employee Martin is one occurrence of the entity Employee.

Entity properties
You can double-click any entity symbol in the diagram to display its
property sheet:
Property

Description

Name

The name of the item which should be clear and meaningful, and should convey the item’s purpose to non-technical
users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the entity

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or
user-defined

Number

Estimated number of occurrences in the physical database
for the entity (the number of records)

Generate

Indicates if the entity will generate a table in a PDM

An entity definition also includes the following properties, each with their
own respective property sheets that can be accessed independently of the
entity:
♦ Attributes
♦ Identifiers
♦ Rules

Creating an entity
There are several ways to create an entity:
♦ From a diagram
52

Chapter 3. Building Conceptual Data Models

♦ From the Browser
♦ From the list of entities
At creation, an entity has a default name including a number. This number is
assigned in the order of creation of objects.

+ For more information on the different ways to create an entity, see
section Creating an object in chapter Managing objects in the General
Features Guide .
v To create an entity from a diagram
1. Click the Entity tool in the Palette.
2. Click anywhere in the diagram.
The following symbol appears at the click position:

3. Click the Pointer tool.

or
Click the right mouse button.
You release the Entity tool.
4. Double-click the new entity symbol in the diagram to display the entity
property sheet.
5. Type a name and a code.

Defining entities in a CDM

6. Click OK.

Modifying entity properties
You can modify the entity properties using the following methods:
♦ From the entity property sheet
♦ From the list of entities

+ For more information on the different ways to modify the entity
properties, see section Modifying object properties in chapter Managing
objects in the General Features Guide .

Copying an entity
You can make a copy of an entity within the same model or between models.
When you copy an entity, the selections for the model options Unique code
and Allow reuse determine the way that identifiers and entity attributes are
copied and named.
The following rules apply to copied entities. The indicated selections for
Unique code and Allow reuse apply to the model that receives the copied
entity:

Chapter 3. Building Conceptual Data Models

Data item options
selected

Result of copying an entity

Unique Code

New entity with new name and code

Allow Reuse

New identifier with new name code
Reuses other entity attributes

Unique Code only

New entity with new name and code
New identifier with new name and code
New attributes with new names and codes

Allow Reuse only

New entity with new name and code
New identifier with same name and code
Reuses other entity attributes

None

New entity with new name and code
New identifier with same name code
New entity attributes with same names and codes

v To copy an entity within a model
1. Select an entity in the CDM.
2. Select Edit ä Copy.
Select Edit ä Paste.

or
Press CTRL and drag the entity to a new position in the diagram.
The new entity appears in the diagram
v To copy an entity to a different model
1. Select an entity in a CDM.
2. Select Edit ä Copy.
Click in the diagram of the target model.
Select Edit ä Paste.

or
Press CTRL and drag the entity to the diagram of the target model.
The new entity appears in the diagram of the target model.

Defining entities in a CDM

Modifying the entity display preferences
You can modify the following display preferences for an entity using the
Tools ä Display Preferences command:

Preference

Display description

All attributes

All attributes including all identifying
attributes

Primary attributes

Only entity attributes
that are primary identifier attributes

Identifying attributes

All attributes that are
defined as identifier
attributes for the entity, including primary
identifier attributes

Display limit

(x) Number of entity
attributes shown depending on defined
value of x. In the
example, x is 5

Identifiers

All identifier attributes
for the entity are listed
at the bottom of the
entity symbol

Stereotype

Stereotype of the entity

Comment

Comment of the entity.
When selected, all
other check boxes are
deselected, except for
Stereotype

Examples

—

Chapter 3. Building Conceptual Data Models

Preference

Display description

Data types

Data type for each
entity attribute

Replace by Domains

Domain for each entity
attribute. You can only
display domains when
the Data type check
box is selected

Domains

Domain of an attribute
in an entity. This display option interacts
with the selection for
Data types. As a result, there are four
display options

Mandatory

The letter beside each entity attribute when it is
mandatory

Identifier indicators

indicators next
to attributes that are
primary identifier attributes

Examples

See Display domain and data
type for options and examples

indicators next
to identifier attributes
that are not primary
identifier attributes
Stereotype (Entity
attributes)

Stereotype of the entity attributes

—

Stereotype (Entity
identifiers)

Stereotype of the entity identifiers

—

Defining entities in a CDM

Display domain and data
type

You can display the domain of an attribute in the symbol of an entity. There
are four display options available:
Selected check box

Result

Data type

Displays only the
data type, if it exists

Domains

Displays only the
domain, if it exists

Data types

Displays both data
type and domain, if
they exist

Domains

Data types
Replace by domains

If domain exists and
data type does not
exist, then displays
domain.
If domain does not
exist and data type
exists, then displays
data type.

Symbol

Chapter 3. Building Conceptual Data Models

Defining entity attributes in a CDM
Entity attributes are data items attached to an entity. When you generate a
Physical Data Model (PDM) from a Conceptual Data Model (CDM), entity
attributes are generated as columns in tables (entities).

Entity attribute properties
You can access entity attribute properties from the list of entity attributes or
from the entity property sheet.
Each entity attribute definition includes the following properties:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the entity attribute

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Data type

Form of the data corresponding to the entity attribute, such as
numeric, alphanumeric, boolean, or others

Length

Maximum length of the data type

Precision

Maximum number of places after the decimal point

Domain

Name of the associated domain

Primary
Identifier

Indicates whether or not the entity attribute is the primary
identifier of the current entity

Displayed

When selected, the attribute is displayed in the entity symbol.
When cleared, the attribute is not displayed in the entity symbol

Mandatory

Indicates whether or not this entity attribute must be assigned a
value

An entity attribute also includes the following properties:

Defining entity attributes in a CDM

Property

Description

Rules

Business rules associated with entity attribute

Standard
Checks

Common data constraints

Additional
Checks

Customized rules for data validation

Notes

Description associated with entity

Creating an entity attribute
There are several ways to create an entity attribute:
♦ From a data item used as an entity attribute
♦ From the attribute list for an entity
At creation, an entity attribute has a default name including a number. This
number is assigned in the order of creation of objects.
Using a data item as an entity attribute
You can use the data item as an entity attribute by attaching it to an entity.
This choice does not create a new data item. The resulting entity attribute
has the same code as the data item.
Reusing a data item as
an entity attribute

If you select Allow Reuse as a data item option, the same data item can be
an entity attribute for more than one entity. However, you cannot reuse a
data item that is an identifier.
Reusing a data item does not create a new data item. The data item and the
corresponding entity attributes have the same code.
Setting data item options

You set data item options by selecting Tools ä Model Options.
A new data item can be added by creating a new one or copying an existing
one as the basis for a new one. The following specific tools are available to
add data items:

Chapter 3. Building Conceptual Data Models

Tool

Description/Effect of Model Options

Add Data Item

This tool is only available if the Allow Reuse option is
selected in Model Options.
This tool displays all model data items. If you click this
tool and select a data item that is unused in the list of entity
attributes, a new data item is created and added to the list.
If you click this tool and select a currently used data item,
the data item is copied and used as the basis for a new data
item

Reuse Data
Item

No new unused data item can be created with this tool.
This tool displays all model data items. If you click this
tool and select a data item that is used in the list of entity
attributes, the data item is copied, added to the list and used
as the basis for a new data item

v To use a data item as an entity attribute
1. Select the Attributes tab in the entity property sheet to display the
corresponding page.
It lists entity attributes associated with the entity.

2. Click the Add Data Item tool.

Defining entity attributes in a CDM

A Selection box appears listing all of the available data items.
3. Select one or more data items.

4. Click OK.
The selected data items are added to the list of entity attributes.
5. Click OK in each of the dialog boxes.
Creating an entity attribute from the list of entity attributes
You can create an entity attribute directly in the list of entity attributes for an
entity. When you create an entity attribute, it is automatically added to the
list of data items. If you select Allow Reuse as a model option, the new data
item can be used as an entity attribute for other entities.
v To create an entity attribute from the list of entity attributes
1. Select the Attributes tab in the entity property sheet to display the
corresponding page.
It lists entity attributes associated with the entity.
2. Click a blank line in the list.

or
Click the Add a Row tool.
An arrow appears at the beginning of the line.

Chapter 3. Building Conceptual Data Models

3. Type an entity attribute name and an entity attribute code.
Automatically reuse a data item

If you select the data item options Allow Reuse and Unique Code and
you type the name of a data item that is already in use, you automatically
reuse the data item.
4. Click OK.

Attaching an entity attribute to a domain
If you attach an entity attribute to a domain, the domain supplies the data
type and related data characteristics. It may also indicate check parameters
and business rules.
v To attach an entity attribute to a domain
1. Double-click an entity in the diagram to display its property sheet.
2. Click the Attributes tab to display the corresponding page.
It list entity attributes associated with the entity.
3. Click an entity attribute to define.
An arrow appears at the beginning of the line.
4. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The entity attribute property sheet opens to the General page.

Defining entity attributes in a CDM

Opening property sheets at last accessed page

You can choose to open property sheets at the last accessed page by
selecting Tools ä General Options ä Dialog, and selecting the option
Keep Last Tab in the Property Sheets groupbox.
5. Select a domain from the Domain dropdown listbox at the bottom of the
dialog box.

or
Click the Ellipsis button at the end of the Domain dropdown listbox.
The list of domains appears.
Select a domain from the list.
Click OK.
6. Click OK.
You return to the Entity attributes page. In the Data Type column, the
data type of the domain replaces the data type previously defined for the
entity attribute.
7. Click OK.

Selecting a data type for an entity attribute
There are two ways to select a data type for an entity attribute:
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Chapter 3. Building Conceptual Data Models

♦ Attach the entity attribute to a domain
The domain dictates a
standard data type, a length, and a level of precision, as well as optional
check parameters.
♦ Manually select the data type
You select a standard data type along
with a length, a level of precision, and optional check parameters
About check parameters

Check parameters indicate data ranges and validation rule. You can attach
check parameters to entity attributes, data items, or domains.
v To select a data type for an entity attribute
1. Double-click an entity in the diagram to display the entity property sheet.
2. Click the Attributes tab to display the corresponding page.
It lists entity attributes associated with the entity.
3. Click the Entity attribute to define.
An arrow appears at the beginning of the line.
4. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The entity attribute property sheet opens to the General page.

Defining entity attributes in a CDM

5. Select a data type from the Data Type dropdown listbox.

or
Click the Question mark button at the end of the Data Type dropdown
listbox.
A list of standard data types supported by PowerDesigner appears.
Select the radio button corresponding to the data type you want to apply.
Undefined data type

If you do not want to select a data type immediately, you can choose the
data type.
6. Type the maximum number of characters for the data type in the Length
box.
7. If the data type can include values that take a decimal point, type the
number of places after the decimal point in the Precision box.
8. Click OK.
You return to the Entity attributes page. The change of data type appears
in the list of entity attributes.

Defining an entity attribute as mandatory or optional
If an entity attribute is mandatory, every entity occurrence must have a value
for that entity attribute. If an entity attribute is optional, entity occurrences
do not have to have a value for that entity attribute.
By default all identifiers are mandatory.
v To define an entity attribute as mandatory or optional
1. Double-click an entity in the diagram to display the entity property sheet.
2. Click the Attributes tab to display the corresponding page.
It lists entity attributes associated with the entity.
3. Click the Entity attribute to define.
An arrow appears at the beginning of the line.
4. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The entity attribute property sheet opens to the General page.

Chapter 3. Building Conceptual Data Models

5. Select the Mandatory check box at the bottom of the dialog box to make
the entity attribute mandatory.

or
Clear the Mandatory check box to make the entity attribute optional.
You cannot clear the Mandatory check box for an identifier because it
must always be mandatory.
6. Click OK in each of the dialog boxes.

Deleting entity attributes
When you delete an entity or entity attributes, data item options determine
whether or not the corresponding data items are also deleted.
The following rules apply to deleted entity attributes:
Data item options

Result of deleting an entity attribute

Unique Code

Deletes entity attribute

Allow Reuse

Does not delete corresponding data item

Unique Code only

Deletes entity attribute
Does not delete corresponding data item

Allow Reuse only

Deletes entity attribute
Deletes corresponding data item if it is not used by
another entity

None

Deletes entity attribute
Deletes corresponding data item

Arranging a list of entity attributes
Each entity has its own list of entity attributes.
In a list of entity attributes, you can arrange items in any order. When you
generate a PDM, the order of entity attributes becomes the order of column
generation.
v To arrange a list of entity attributes
1. Double-click an entity symbol to display the entity property sheet.
2. Click the Attributes tab to display the corresponding page.

Defining entity attributes in a CDM

It lists the data items attached to the entity.
3. Select one or more entity attributes in the list.
4. Use the arrow buttons at the bottom left corner of the list to move the
items in the list.
5. Click OK.

Chapter 3. Building Conceptual Data Models

Defining identifiers in a CDM
An identifier is an entity attribute, or a combination of entity attributes,
whose values uniquely identify each occurrence of the entity. An identifier is
the CDM equivalent of a primary key or an alternate key in a physical data
model (PDM).
Each entity must have at least one identifier. If an entity has only one
identifier, it is designated by default as the primary identifier for the entity. A
primary identifier is the main identifier for an entity.

Designating an identifier
You designate an identifier from the Identifiers page of the entity property
sheet.

+ For information on how to display identifiers in an entity symbol, see
section “Modifying the entity display preferences” on page 56.
You can also create an identifier from the list of entity attributes: click the
Attributes tab in the entity property sheet, select one or more attributes to
include into the identifier and click the Create Identifier tool.
v To designate an identifier
1. Double-click an entity in the diagram to display the entity property sheet.
2. Click the Identifiers tab to display the corresponding page.
It lists identifiers defined for the entity.

Defining identifiers in a CDM

3. Click a blank line in the list.

or
Click the Add a Row tool.
An arrow appears at the beginning of the line.
4. Type an identifier name and code.
5. Click Apply.
The constraint name and code are committed.
6. Double-click the new identifier name to display the identifier property
sheet.
7. Click the Attributes tab to display the corresponding page.
It lists all entity attributes defined for the identifier. At identifier creation,
the list is empty.
8. Click the Add Attributes tool.
A list of entity attributes defined for the entity appears.

Chapter 3. Building Conceptual Data Models

9. Select check boxes for one or more entity attributes that you want to
designate as an identifier.
10. Click OK in each of the dialog boxes.

Adding attributes to an entity identifier
You can add attributes to an entity identifier.

Defining identifiers in a CDM

v To add attributes to an identifier
1. Click the Attributes tab in the identifier property sheet to display the
corresponding page.
It lists the attributes currently defined for the identifier.
2. Click the Add Attributes tool.
A list of entity attributes defined for the entity appears.

3. Select check boxes for one or more entity attributes that you want to
designate as an identifier.
4. Click OK in each of the dialog boxes.

Designating a primary identifier
A primary identifier is an identifier that has been designated as the main
identifier for the entity. It generates a primary key in a PDM.
v To designate a primary identifier
1. Double-click an entity in the diagram to display the entity property sheet.
2. Click the Identifiers tab to display the corresponding page.
It lists the Identifiers defined for the entity.
3. Select an identifier from the list.
An arrow appears at the beginning of the line.
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Chapter 3. Building Conceptual Data Models

4. Click the Property tool.

or
Double-click the arrow at the beginning of the line.
The identifier property sheet appears.

5. Select the Primary Identifier check box.
6. Click OK.
You return to the Identifiers page. The P column is selected for the new
primary identifier.
Item not visible in list

Modifying an identifier name or code from the list
You can modify an identifier name and code using the following methods:
♦ From the identifier property sheet accessible from the entity property
sheet

Defining identifiers in a CDM

♦ From the list of identifiers

+ For more information on the different ways to modify the identifier
properties, see section Modifying object properties in chapter Managing
objects in the General Features Guide .

Chapter 3. Building Conceptual Data Models

Defining relationships in a CDM
A relationship is a link between entities. For example, in a CDM that
manages human resources, the relationship Member links the entities
Employee and Team, because employees can be members of teams. This
relationship expresses that each employee works in a team and that each
team has employees.
An occurrence of a relationship corresponds to one instance of each of the
two entities involved in the relationship. For example, the employee Martin
working in the Marketing team is one occurrence of the relationship
Member.
Relationships and
association

Relationships are used in the Entity Relationship (ER) and IDEF1X
modeling methodologies. In PowerDesigner you can also use associations
used in the Merise methodology to link entities. You can use either
relationships or associations exclusively, or combine the two methodologies
in the same model.

+ For more information on using associations, see section “Defining
associations in a CDM” on page 95.
This section analyzes relationships in the Entity Relationship methodology,
for more information on IDEF1X, see section CDM Options in chapter
Conceptual Data Model Basics.

Relationship properties
You can double-click any relationship symbol in the diagram to display its
properties:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the relationship

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Entity1

The two entities linked by the relationship

Entity2

Defining relationships in a CDM

Property

Description

Generate

Indicates to generate a reference in PDM

Cardinalities

Contains data about cardinality as the number of instances of
one entity in relation to another entity

Creating a relationship
There are several ways to create a relationship between entities:
♦ From a diagram
♦ From the Browser
♦ From the list of relationships
At creation, a relationship has a default name including a number. This
number is assigned in the order of creation of objects.
When you create a relationship from the Browser or from the list of
relationships, you must previously define source and destination objects for
the relationship.

+ For more information on the different ways to create a relationship, see
section Creating an object in chapter Managing objects in the General
Features Guide .
v To create a relationship from a diagram
1. Click the Relationship tool in the Palette.
2. Click inside the first entity and while continuing to hold down the mouse
button, drag the cursor to a second entity. Release the mouse button
inside the second entity.
A relationship symbol appears between the two entities.

Dragging a relationship to a different entity

You change the entity at either end of a relationship by clicking the
relationship to select it, holding the CTRL key down, and dragging one
of the attach points to a different entity.

Chapter 3. Building Conceptual Data Models

3. Click the Pointer tool.

or
Click the right mouse button.
You release the Relationship tool.
4. Double-click the new relationship symbol in the diagram to display the
relationship property sheet. It displays the definition of the selected
relationship.
5. Type a relationship name and a relationship code.

Opening the property sheet of objects at ends

You can open the property sheet of the source and destination objects
by clicking the Entity 1 and Entity 2 buttons located in the upper part of
the flow property sheet.
6. Type or select relationship properties as required in the tabbed pages.

Defining relationships in a CDM

7. Click OK.
Displaying relationships from the entity property sheet

Relationships linked to an entity are also displayed in the entity property
sheet. You can display those relationships from the Relationships tabbed
page of the Dependencies page.

Creating a reflexive relationship
A reflexive relationship is a relationship between an entity and itself.
Example

The reflexive relationship Supervise expresses that an employee (Manager)
can supervise other employees.

Getting neat relationship lines

To obtain clean lines with rounded corners when you create a reflexive
relationship, select Display Preferences ä Format ä Relationship and
modify the Line Style with the appropriate type from the Corners dropdown
listbox.
v To create a reflexive relationship
1. Click the Relationship tool in the Palette.
2. Click inside the first entity and while continuing to hold down the mouse
button, drag the cursor to a space next to the entity.
3. Click the entity.
A relationship symbol loops back to the same entity.

Chapter 3. Building Conceptual Data Models

Entity dependencies

In the Dependencies page of the entity, you can see two identical occurrences of the relationship, this is to indicate that the relationship is reflexive
and serves as origin and destination for the link

Modifying relationship properties
You can modify the relationship properties using the following methods:
♦ From the relationship property sheet
♦ From the list of relationships

+ For more information on the different ways to modify the relationship
properties, see section Modifying object properties in chapter Managing
objects in the General Features Guide .

Defining a code option for relationships
You can define the following code option for relationships:
Option

Result when selected

Result when cleared

Unique code

Each relationship has a
unique code

Different relationships can have
the same code

If you do not select Unique Code, two relationships can have the same code.
In this case, you differentiate the relationships by the entities they link.
Error message

The following error message appears when the option you choose is
incompatible with the current CDM:
Error message

Solution

Unique Code option could not be
selected because at least two relationships have the same code:
relationship_code.

Change the code of one relationship

Defining relationships in a CDM

v To define a code option for relationships
1. Select Tools ä Model Options.
The Model Options dialog box opens to the Model Settings page.

2. Select the Unique Code check box in the Relationship groupbox to
require a unique code for each relationship.

or
Clear the Unique Code check box in the Relationship groupbox to allow
more than one relationship to have the same code.
3. Click OK.

Defining cardinality for relationships
Cardinality indicates the number of instances (none, one, or many) of an
entity in relation to another entity. You can select the following values for
cardinality:

Chapter 3. Building Conceptual Data Models

Cardinality

Symbol

Description

One-to-one

<1..1>

One instance of the first entity can correspond
to only one instance of the second entity

One-to-many

<1..n>

One instance of the first entity can correspond
to more than one instance of the second entity

Many-to-one

More than one instance of the first entity can
correspond to the same one instance of the
second entity

Many-to-many

More than one instance of the first entity can
correspond to more than one instance of the
second entity

The Cardinalities page contains a groupbox for each direction of the
relationship. The title of the groupbox takes the following form:
’EntityA’ to ’EntityB’

The following properties apply to each direction of the relationship:
Property

Description

Dominant role

In a One to One relationship, indicates to generate a
reference in the PDM for this direction of the relationship
only

Role name

Text that describes the relationship of EntityA to EntityB

Dependent

Indicates that each instance of the EntityA is identified by
an instance of EntityB

Mandatory

Indicates that each instance of the EntityA requires an
instance of the EntityB

Cardinality

Maximum and minimum number of instances of EntityA
in relation to EntityB (if mandatory, at least 1). You can
indicate the following cardinalities:
0..1
0..n
1..1
1..n

Termination points

In a diagram, termination points indicate cardinality at each end of a
relationship. A termination with a single contact point denotes a cardinality

Defining relationships in a CDM

of one. A termination with three contact points denotes a cardinality of
many.
Termination point

Cardinality

One

Many

+ For more information on IDEF1X cardinality notation, see section CDM
options in chapter Conceptual Data Model Basics.
v To define cardinality
1. Double-click the relationship to display the relationship property sheet.
It displays the definition of the selected relationship.
2. Click the Cardinalities tab to display the corresponding page.
3. Select one of the cardinality radio buttons.
4. Click OK.
Example

The Cardinalities page below indicates that an employee must belong to one
and only one division, while a division must include one or more employees.

Chapter 3. Building Conceptual Data Models

Defining a mandatory relationship
The property Mandatory indicates whether the relationship between entities
is mandatory or optional. You define options from the point of view of both
entities in the relationship.
Termination points

In the resulting relationship symbol, a bar represents a mandatory
relationship. A circle represents an optional relationship.

Defining relationships in a CDM

Termination
point

Existence

Cardinality

Description

Mandatory

One

Must exist one and only one

Mandatory

Many

Must exist one or more

Optional

One

May exist one, or none

Optional

Many

May exist one or more, or
none

+ For more information on IDEF1X existence notation, see section CDM
options in chapter Conceptual Data Model Basics.
v To define a mandatory relationship
1. Double-click the relationship symbol to display the relationship property
sheet.
2. Click the Cardinalities tab to display the corresponding page.
3. Select the Mandatory check box in one or both of the groupboxes
corresponding to a relationship direction.
4. Click OK.
Example

The Cardinalities page below indicates that the subcontract relationship is
optional from customer to project, and mandatory from project to customer.
Each project must have a customer, while each customer does not have to
have a project.

Chapter 3. Building Conceptual Data Models

Defining a dependent relationship
In a dependent relationship, one entity is partially identified by another.
Each entity must have an identifier. In some cases, however, the attributes of
an entity are not sufficient to identify an occurrence of the entity. For these
entities, their identifiers incorporate the identifier of another entity with
which they have a dependent relationship.
Example

An entity named Task has two entity attributes, TASK NAME and TASK
COST. A task may be performed in many different projects and the task cost
will vary with each project. To identify each occurrence of TASK COST the
unique Task entity identifier is the compound of its Task name entity
attribute and the Project number identifier from the Project entity.
Many to many relationship

A many-to-many relationship cannot be a dependent relationship.
Termination points

In the resulting model, a triangle just before the termination point of the
relationship indicates a dependent relationship. The triangle points away

Defining relationships in a CDM

from the dependent entity.
For example, here Entity B depends on Entity A.

The bar indicates that the relationship in not only dependent, but also
mandatory. The single contact point indicates the one-to-one cardinality of
the relationship. In this case, for each occurrence of Entity B there must be
only one occurrence of Entity A.
The tip of the triangle shown above has a bar to note a mandatory
relationship: every occurrence of Entity A requires an occurrence of Entity
B.

+ For more information on IDEF1X notation, see section CDM options in
chapter Conceptual Data Model Basics.
v To define a dependent relationship
1. Double-click the relationship symbol to display the relationship property
sheet.
It displays the definition of the selected relationship.
2. Click the Cardinalities tab to display the corresponding page.
3. Select or clear the Dependent check box in each groupbox corresponding
to a relationship direction.
4. Click OK.
Example

The property sheet below shows that the Task entity is dependent on the
Project entity.

Chapter 3. Building Conceptual Data Models

The relationship pictured here expresses this dependency.

The circle at the tip of the triangle indicates that occurrences of the Project
entity do not require an occurrence of the Task entity. But an occurrence of
the Task entity requires an occurrence of the Project entity on which it
depends.

Defining a dominant relationship
In a one-to-one relationship, you can define one direction of the relationship
as dominant. If you define a dominant direction, the one-to-one relationship
generates one reference in the PDM. The dominant entity becomes the
parent table. If you do not define a dominant direction, the one-to-one
relationship generates two references.

Defining relationships in a CDM

v To define a dominant relationship
1. Double-click a relationship symbol in the diagram to display the
relationship property sheet.
It displays the definition of the selected relationship.
2. Click the Cardinalities tab to display the corresponding page.
3. Select the One to One check box.
4. Select the direction for the dominance from the Dominant Role
dropdown listbox.
5. Click OK.
Example

For example, in the property sheet below, the Author to Picture direction is
dominant in the relationship.

The relationship pictured here shows the one-to-one relationship.

Chapter 3. Building Conceptual Data Models

In a PDM, this relationship generates the following reference: Author is the
parent table, and its primary key migrates to the Picture table as foreign key.

Changing a relationship into an associative entity
You can transform a relationship into an associative entity linked by two
relationships. Next, you can attach entity attributes to this associative entity,
that you could not attach to the relationship.
The associative entity gets the name and code of the relationship. The two
new relationships handle cardinality properties.
v To change a relationship into an associative entity
1. Right-click a relationship symbol.
The relationship contextual menu appears.
2. Select Change to Entity ä Standard from the contextual menu.
Customizing entity wizard

You can also select Change to Entity ä Wizard from the contextual
menu. A step by step wizard takes you through a more detailed
procedure for defining an associative entity.
An associative entity with two relationships replaces the relationship.
The associative entity takes the name of the original relationship.

Creating an associative entity using the Change to Entity Wizard
You can use the Change to Entity wizard to transform a relationship into an
associative entity linked by two relationships.
You create the associative entity in three stages. Each stage corresponds to a
page in the wizard process. You move through each stage by clicking the
Next button.
You can enter the following information for each stage of the wizard:

Defining relationships in a CDM

Stage

Description

Customizing
entity

You type the name and code for the new entity. You can also
type a description in the Comment box

Customizing
Relationship
(New entity
to first entity)

You type the name and code for the relationship that will
be created between the first entity and the new entity. The
first entity is defined as Entity 1 in the property sheet for the
original relationship. You can also enter a role name for the
relationship and a cardinality value

Customizing
Relationship
(New entity
to second
entity)

You type the name and code for the relationship that will be
created between the new entity and the second entity. The
second entity is defined as Entity 2 in the property sheet for
the original relationship. You can also enter a role name for
the relationship and a cardinality value

v To create an associative entity using the Change to Entity Wizard
1. Right-click a relationship symbol.
A contextual menu appears.
2. Select ä Change to Entity ä Wizard to display the Customizing Entity
page.
3. Type an entity name and an entity code.
4. Click Next.
The Customizing Relationship page appears.
5. Fill in details for the first entity to new entity relationship.
6. Click Next.
The second Customizing Relationship page appears.
7. Fill in details for the new entity to second entity relationship.
8. Click Finish.
The associative entity with two relationships replaces the relationship.

Sorting the list of relationships
You can sort the list of relationships alphabetically or in reverse alphabetical
order by any list property.
The listed order is indicated by an arrowhead that appears at the end of the
column heading for the property as follows:
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Chapter 3. Building Conceptual Data Models

Arrow type

Listed order

Down arrow

Alphabetically

Up arrow

Reverse alphabetically

For example, when you click the column heading Name, the relationships
are listed by relationship name alphabetically when the down arrow is
indicated, and in reverse order when the up arrow is indicated.
Item not visible in list

To make an item visible in a list, click the Customize Columns and Filter
tool in the list, and from the list of filter options that appears, select the
appropriate item check box and click OK.
v To sort the list of relationships
1. Select Model ä Relationships to display the list of relationships.
2. Click a column header.
The listed references are ordered by the indicated property.
3. Click OK.

Relationship examples
This section shows the graphic representation of various relationship
properties.
One-to-many relationship

Description

Each division may have zero
or more employees
Each employee may belong to
zero or one division
Each division must have one or
more employees
Each employee may belong to
zero or one division
Each division may have zero
or more employees
Each employee must belong to
one and only one division

Defining relationships in a CDM

One-to-many relationship

Description

Each division must have one or
more employees
Each employee must belong to
one and only one division
Each division may have zero
or more employees
Each employee must belong to
one and only one division
Each employee is identified
uniquely by division number
and employee number
Each division must have one or
more employees
Each employee must belong to
one and only one division
Each employee is identified
uniquely by division number
and employee number

One-to-one relationship

Description

Each team works on zero or
one project
Each project is managed by
zero or one team
Each team works on one and
one project only
Each project is managed by
zero or one team
Each team works on zero or
one project
Each project is managed by
one and one team only

Chapter 3. Building Conceptual Data Models

Many-to-many relationship

Description

Each division may have zero
or more employees
Each employee may belong to
zero or more divisions
Each division must have one or
more employees
Each employee may belong to
zero or more divisions
Each division may have zero
or more employees
Each employee must belong to
one or more divisions
Each division must have one or
more employees
Each employee must belong to
one or more divisions

Modifying the relationship display preferences
You can modify the following display preferences for a relationship using
the Tools ä Display Preferences command:
Preference

Display description

Name

Name or code of the relationship*

Role

Role of each direction in the relationship

Cardinality

Minimum and maximum number of instances that the
first entity can have relative to the second entity

Dominance

Letter D on the dominant entity side of the relationship

Stereotype

Stereotype of the relationship

*Displayed text depends on whether the Name or Code radio button is
selected.

Defining relationships in a CDM

Modifying a relationship graphically
From the CDM graphic, you can modify a relationship as follows:
♦ Bend a relationship symbol
♦ Straighten a relationship symbol
♦ Drag a relationship to a different entity
Bending a relationship symbol
v To bend a relationship symbol
1. Press CTRL while you click a point on the relationship to insert an angle.
The point becomes a handle.
2. Release CTRL .
3. Drag and drop the handle to create the bend.
Straightening a relationship symbol
v To straighten a relationship symbol
1. Click a relationship symbol that has angles.
Handles appear on the relationship symbol.
2. Press CTRL while you click a handle.
The handle and its angle disappear.
Dragging a relationship to a different entity
v To drag a relationship to a different entity
1. Click a relationship.
2. Press CTRL while you drag one of its attach points to a different entity.

Chapter 3. Building Conceptual Data Models

Defining associations in a CDM
An association is a connection between entities. In the Merise modeling
methodology an association is used to connect several entities that each
represents clearly defined objects, but are linked by an event, which may not
be so clearly represented by another entity.
Each instance of an association corresponds to an instance of each entity
linked to the association.
Example

Three entities VIDEOK7, CLIENT, and STORE contain video cassette,
client, and store information. They are linked by an association which
represents a video cassette rental (K7RENTAL). The K7RENTAL
association also contains the attributes DATE and STAFF_ID, which give
the date of the rental, and the identity of the staff member who rented out the
video cassette.

When you generate a PDM, K7RENTED is generated as a table with five
columns, STORE_ID,K7_ID, CLIENT_ID, DATE, and STAFF_ID.

Defining associations in a CDM

In PowerDesigner you can use associations exclusively in your CDM, or use
both associations and relationships in the same model.
Association links

An association is connected to an entity by an association link. An
Association Link symbolizes the role and the cardinality between an
association and an entity.

Association properties in CDM
You can double-click any association symbol in the diagram to display its
properties:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the association

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Number

Estimated number of occurrences in the physical database for
the association (the number of records)

Generate

Indicates if the association will generate a table in a PDM

Attributes

Data item attached to an association

Rules

Business rules associated with the association

Association link properties
You can double-click any association link symbol in the diagram to display
its properties:

Chapter 3. Building Conceptual Data Models

Property

Description

Entity

Entity connected by the association link

Association

Association connected by the association link

Role

Label indicating the role of the association link

Identifier

Indicates if the entity is dependent on the other entity

Cardinality

Number of occurrences (one or many) of one entity to another
entity

Stereotype

Sub-classification used to extend the semantics of an object
without changing its structure; it can be predefined or userdefined

Creating an association in a CDM
There are several ways to create an association:
♦ From a diagram
♦ From the Browser
♦ From the list of associations
At creation, an association has a default name including a number. This
number is assigned in the order of creation of objects.

+ For more information on the different ways to create an association, see
section Creating an object in chapter Managing objects in the General
Features Guide .
v To create an association from a diagram
1. Click the Association Link tool in the Palette.
2. Click inside the first entity and while continuing to hold down the mouse
button, drag the cursor to a second entity. Release the mouse button.
An association symbol is created between the two entities.

3. Double-click the new association symbol in the diagram to display the
association property sheet.

Defining associations in a CDM

4. Type an association name and an association code.

5. Click OK.

Creating an association link
There are several ways to create an association link between an entity and an
association:
♦ From a diagram
♦ From the list of associations links
Creating an association link from a diagram:
v To create an association link from a diagram
1. Click the Association Link tool in the Palette.
2. Click inside the first entity and while continuing to hold down the mouse
button, drag the cursor to a second entity. Release the mouse button.
An association symbol with two associations links is created between the
two entities.

Chapter 3. Building Conceptual Data Models

3. Double-click one of the two associations links symbols in the diagram to
open the association link property sheet.
It displays the definition of the selected association link.
4. Type or select association link properties as required.

5. Click OK.
Creating an association link from the list of associations links
v To create an association link from the list of associations links
1. Select Model ä Links to display the list of associations links.
2. Click a blank line in the list.

or
Click the Add a Row tool.
An arrow appears at the beginning of the line. is displayed by
default in the Entity and Association columns.

Defining associations in a CDM

3. Click the down arrowhead in the Entity column and select an entity from
the dropdown listbox.
4. Click the Association column to display the down arrowhead and select
an association from the dropdown listbox.
5. Click the Cardinality of role column to display the down arrowhead and
select a cardinality from the dropdown listbox.
6. Click OK.
A symbol for this association link is created between the entity and the
association in the current diagram.

Creating a reflexive association in a CDM
A reflexive association is a relationship between an entity and itself.
Example

100

The reflexive association Manager expresses that an employee (Manager)
can manage other employees.

Chapter 3. Building Conceptual Data Models

v To create a reflexive association
1. Click the Association Link tool in the Palette.
2. Click inside the entity and while continuing to hold down the mouse
button, drag the cursor to a space next to the entity.
3. Click the entity.
An association symbol loops back to the same entity.

Defining cardinality for an association link
Cardinality indicates the number of occurrences (one or many) that one
entity has relative to another. You define the cardinality for each association
link between the association and the entity.
The cardinality of an association link can have the following values:

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Defining associations in a CDM

Cardinality

Description

0,1

There can be zero or one occurrence of the association in
relation to one instance of the entity. The association is not
mandatory

0,n

There can be zero or many occurrences of the association in
relation to one instance of the entity. The association is not
mandatory

1,1

One occurrence of the entity can be related to only one
occurrence of the association. The association is mandatory

1,n

One occurrence of the entity can be related to one or many
occurrences of the association. The association is mandatory

You can change the default format of cardinalities from the registry:
HKEY_CURRENT_USER\Software\Sybase\PowerDesigner 11\ModelOptions\
Conceptual Options
CardinalityNotation=1 (0..1) or 2 (0,1)

v To define cardinality for an association link
1. Double-click the association link between an association and an entity to
display the association link property sheet.

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2. Select a cardinality from the Cardinality dropdown listbox.
3. Click OK.
You can repeat the procedure for each association link.

Defining a dependent association in a CDM
In a dependent association, one entity is partially identified by another. Each
entity must have an identifier. In some cases, however, the attributes of an
entity are not sufficient to identify an occurrence of the entity. For these
entities, their identifiers incorporate the identifier of another entity with
which they have a dependent association.
Example

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Defining associations in a CDM

When you generate a PDM, the TASK table contains the PROJECT
NUMBER column as a foreign key, which is also a primary key column.
The primary key therefore consists of both PROJECT NUMBER and TASK
NAME columns.

Association link identifiers and associations

The same association can not have two identifier association links.
v To define a dependent association
1. Double-click an association link symbol to display the association link
property sheet.
2. Select the Identifier check box.
3. Click OK.
The cardinality of the association link is enclosed in parenthesis to
indicate that the association link is an identifier.

Changing an association into an associative entity
You can transform an association into an associative entity linked by two
associations. The associative entity gets the name and code of the
association. The two new associations handle cardinality properties.
Example

Two entities PROJECT MANAGER and CONTRACTOR are linked by the
association WORKS ON PROJECT WITH:

You can represent this association with an associative entity:

The two new associations can be represented as follows:

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Chapter 3. Building Conceptual Data Models

v To change an association into an associative entity
1. Right-click an association symbol.
The association contextual menu appears.
2. Select Change to Entity from the contextual menu.
An associative entity that is linked to two associations replaces the
original association. The associative entity takes the name of the original
association.

Creating an association attribute
There are several ways to create an association attribute:
♦ From a data item used as an association attribute
♦ From the attribute list for an association
At creation, an association attribute has a default name including a number.
This number is assigned in the order of creation of objects.
Using a data item as an association attribute
You can use a data item defined in the model as an attribute for an
association.
Allow Reuse

If the model option Allow Reuse is not selected, you can not create an
association attribute by reusing an existing data item. In this case the Add
Data Items tool is not available.

105

Defining associations in a CDM

v To use a data item as an association attribute
1. Double-click the association in the diagram to display the association
property sheet.
2. Click the Attributes tab to display the corresponding page.
It lists attributes associated with the association.

3. Click the Add Data items tool.
A Selection box appears listing all of the available data items.
4. Select one or more data items.

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5. Click OK.
The selected data items are added to the list of attributes for the
association.
6. Click OK in each of the dialog boxes.
Creating an association attribute from the list of association attributes
You can create an association attribute directly in the list of attributes for an
association. When you create an association attribute, it is automatically
added to the list of data items. If you select Allow Reuse as a model option,
the new data item can be used as an attribute for other associations or
entities.
v To create an association attribute from the list of association attributes
1. Double-click the association to display the association property sheet.
2. Click the Attributes tab to display the corresponding page.
It lists association attributes associated with the association.
3. Click a blank line in the list.

or
Click the Add a Row tool.
An arrow appears at the beginning of the line.

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Defining associations in a CDM

4. Type an association attribute name and an association attribute code.
Automatically reuse a data item

If you select the data item model options Allow Reuse and Unique
Code and you type the name of a data item that is already in use, you
automatically reuse the data item.
5. Click OK.

Modifying the association display preferences in a CDM
You can modify the following display preferences of an association using
the Tools ä Display Preferences command:
Group box

Preference

Display description

Association

Attributes

Name or code of the association*

Display Limit

Maximum number of attributes displayed in
symbol

Stereotype

Stereotype of the association

Comment

Comment of the association. When selected, all other check boxes are deselected,
except for Stereotype

Data types

Data type of association attribute

Replace by
domains

Domain for each association attribute. You
can only display domains when the Data
types check box is selected

Domains

Domain of each association attribute

Mandatory

Letter M beside each mandatory association
attribute

Stereotype

Stereotype of the association attributes

Association
attributes

*Displayed text depends on whether the Name or Code radio button is
selected.
Display domain and data
type

108

You can display the domain and data types in the symbol of an association.
There are four display options available:

Chapter 3. Building Conceptual Data Models

Selected checkbox

Result

Data types

Displays only the
data type, if it exists

Domains

Displays only the
domain, if it exists

Data types

Displays both data
type and domain, if
they exist

Domains

Data types
Replace by domains

Symbol

If domain exists and
data type does not
exist, then displays
domain.
If domain does not
exist and data type
exists, then displays
data type.

Moving text on a relationship symbol

When a relationship symbol displays text, the text position is based on the
position of handles. You can add a handle on the relationship symbol by
pressing CTRL while you click the symbol.

Modifying the association link display preferences
You can modify the following display preferences of an association link
using the Tools ä Display Preferences command:
Preference

Description

Role

Displays the role of the association link

Cardinality

Displays the cardinality of the association link

Stereotype

Stereotype of the association link

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Defining inheritances in a CDM

Defining inheritances in a CDM
Inheritance allows you to define an entity as a special case of a more
general entity. The entities involved in an inheritance have many similar
characteristics but are nonetheless different. The general entity is known as a
supertype (or parent) entity and contains all of the common characteristics.
The special case entity is known as a subtype (or child), entity and contains
all of the particular characteristics.
Between entities, it is also possible to define an inheritance link. In an
inheritance link, one or more subtype (or child) entities inherit, at the
physical level, all or part of the entity attributes carried by one supertype (or
parent) entity.
The Account entity below represents all the bank accounts in the
information system. It includes two subtypes: checking accounts and
savings accounts. The notion of inheritance represents the entities Checking
and Savings as specialized types of the parent entity Account.

Inheritance properties
You can double-click any inheritance symbol in the diagram to display its
properties:

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Chapter 3. Building Conceptual Data Models

Property

Description

Name

The name of the item which should be clear and meaningful, and should convey the item’s purpose to nontechnical users

Code

The technical name of the item used for generating code
or scripts, which may be abbreviated, and should not
generally include spaces

Comment

Descriptive label for the inheritance link

Stereotype

Sub-classification used to extend the semantics of
an object without changing its structure; it can be
predefined or user-defined

Parent

Name of the parent entity

Mutually exclusive children

Indicates if only one child can exist for one occurrence
of the parent entity.

Complete

Indicates that all instances of the parent entity (surtype)
must belong to one of the children (subtypes). For example, entity Person has 2 sub-types Male and Female;
each instance of entity Person is either a male or a
female

An inheritance link definition also includes the following properties, which
are defined on associated property sheets:

Inheritance display

Property

Description

Generation

Group of properties that affect physical implementation

Children

List of child entities

Notes

Description associated with inheritance link

Rules

Business rules attached to the inheritance link

Depending on the model notation, the inheritance symbol displays the
inheritance status:

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Defining inheritances in a CDM

IDEF1X

E/R and Merise notation

Description

Standard

—

Mutually exclusive
inheritance
Complete inheritance

—

Mutually exclusive and
complete inheritance

Creating an inheritance link
You can create an inheritance link graphically in the diagram by dragging
and dropping an inheritance link symbol from the child entity to the parent
entity using the Inheritance tool.
v To create an inheritance link
1. Click the Inheritance tool in the Palette.
2. Click the child entity, while continuing to hold down the mouse button,
drag the cursor to the parent entity. Release the mouse button inside the
child entity.
The link appears between the two entities and has a half-circle in the
middle and an arrowhead that points to the parent entity.

3. If you want to create additional child entities for the same link, drag and
drop an inheritance link from the half-circle to the additional child entity.
The symbol links all the child entities to the parent.

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Chapter 3. Building Conceptual Data Models

Dragging an inheritance link to a different child entity

You can change the child entity at the end of an inheritance link by
clicking the inheritance link and holding down CTRL as you drag one of
its attach points to a different entity.
4. Double-click the new link in the diagram to display the inheritance
property sheet.
5. Type an inheritance name and an inheritance code.

6. Click OK.

Adding a child entity to an inheritance link
You can add a child entity to an inheritance link.

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Defining inheritances in a CDM

v To add a child entity to an inheritance link
1. Double-click an inheritance symbol to display the inheritance property
sheet.
2. Click the Children tab to display the corresponding page.

3. Click the Add Children tool.
A selection box appears. It lists the entities available in the model.
4. Select one or more entities.

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Chapter 3. Building Conceptual Data Models

5. Click OK.
The new entity is added to the list of child entities on the Children page.
6. Click OK.
The new child entity is linked to the inheritance symbol in the diagram.

Making inheritance links mutually exclusive
When an inheritance link is mutually exclusive between children, one
occurrence of the parent entity cannot be matched to more than one child
entity.
This information is for documentation only and has no impact in generating
the PDM.

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Defining inheritances in a CDM

v To make an inheritance link mutually exclusive
1. Double-click the inheritance link in the diagram to display the inheritance
link property sheet.

2. Select the Mutually Exclusive Children check box.
3. Click OK.
The mutually exclusive inheritance links display an X on the half-circle
symbol.

The inheritance link shown above is mutually exclusive. It means that an
account is either checking or savings, never both.

Generation mode properties
Generation mode defines the physical implementation of an inheritance
structure.
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In the CDM, the generation mode indicates which entities in an inheritance
structure should correspond to tables in the PDM, as follows:
Generation mode

Generates table(s)
corresponding to

Which have the following
properties

Generate parent

Parent entity

Inherits entity attributes of
each child entity
Is affected by child entity
relationships.
Contains reference to any
table which has a many-toone relationship with child
entity

Generate children

Each child entity

Inherits all entity attributes of
the parent entity

Each child entity

Inherits only the identifier of
the parent entity

Inherit all attributes
Generate children
Inherit only primary
attributes
Primary keys for child tables

When you generate a child table, its primary key is the concatenation of the
child entity identifier and the parent entity identifier.

Defining generation mode
You define the generation mode which specifies the physical implementation
of an inheritance structure.
Generating specifying
attributes

In the case of parent only generation, you can choose to define a specifying
attribute to differentiate occurrences of a child.

+ For more information on specifying attribute properties see section
“Specifying entity attribute properties” on page 118.

+ For more information on defining a specifying attribute, see section
“Defining a specifying entity attribute” on page 120.
v To define generation mode
1. Double-click the inheritance link in the diagram to display the inheritance
property sheet.
2. Click the Generation tab to display the corresponding page.

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Defining inheritances in a CDM

3. Select Generate Parent.

or
Select Generate Children.

or
Select both Generate Parent and Generate Children.
4. If you selected Generate Children, do one of the following actions:
Click the Inherit All Attributes radio button.

or
Click the Only Primary Attributes radio button. Primary attributes are the
attributes defined in the primary identifier.
5. Click OK.

Specifying entity attribute properties
A specifying entity attribute is an entity attribute that is defined for a
parent entity which differentiates occurrences of each child. It only applies
to parent only generation.
Example

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In the example below, the TITLE entity has two children,
NONPERIODICAL and PERIODICAL.

Chapter 3. Building Conceptual Data Models

As only the parent table TITLE will be generated in a PDM, a specifying
entity attribute PERIODICAL is defined for the inheritance link to
differentiate between the two child entities.
In the PDM, each of the child entity attributes will generate columns in the
table TITLE, however the specifying entity attribute PERIODICAL will
generate a corresponding column PERIODICAL. The values of this column
indicate whether an instance of TITLE is a periodical or not.

You can specify the following properties for a specifying entity attribute:
Property

Description

Name

The name of the item which should be clear and meaningful,
and should convey the item’s purpose to non-technical users

Code

The technical name of the item used for generating code or
scripts, which may be abbreviated, and should not generally
include spaces

Comment

Descriptive label for the specifying entity attribute

Data type

Data type that you want to apply to the specifying entity
attribute

Length

Maximum length of the data type

Precision

Number of places after the decimal point, for data values that
can take a decimal point

Domain

Name of the associated domain

Mandatory

Indicates whether or not the specifying entity attribute must be
assigned a value

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Defining inheritances in a CDM

Defining a specifying entity attribute
You define a specifying entity attribute only in the case of parent only
generation. In a PDM the specifying attribute differentiates occurrences of
each child. There are several ways to create a specifying attribute:
♦ From a data item used as a specifying attribute
♦ From the specifying attribute list for an inheritance
Using a data item as a specifying attribute
You can use a data item defined in the model as an specifying attribute.
Allow Reuse

If the model option Allow Reuse is not selected, you can not create an
specifying attribute by reusing an existing data item. In this case the Add
Data Item tool is not available.
v To use a data item as a specifying attribute
1. Double-click an inheritance symbol to display the inheritance property
sheet.
2. Click the Generation tab to display the corresponding page.

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3. Select the Generate Parent check box.
4. Clear the Generate Children check box.
5. Click the Add Data items tool.
A Selection box appears listing all of the available data items.
6. Select a data item.
7. Click OK.
The selected data item is added to the list of specifying attributes for the
inheritance.
8. Click OK.
Using the Generate option

The option Generate Children generates a table for each child in the
inheritance. If you do not select Generate Children, you can control the
generation of child tables using the option Generate in the property sheet
of each child entity.
Creating a specifying attribute from the specifying attributes list for an inheritance
You can create a specifying attribute directly in the list of specifying
attributes for an inheritance. When you create an specifying attribute, it is
automatically added to the list of data items. If you select Allow Reuse as a
model option, the new data item is available to be re-used as an attribute for
an entity, association, or inheritance.
v To create a specifying attribute from the specifying attributes list
for an inheritance
1. Double-click the inheritance symbol to display the inheritance property
sheet.
2. Click the Generation tab to display the corresponding page.
3. Select the Generate Parent check box.
4. Clear the Generate Children check box.
5. Click a blank line in the list.

or
Click the Add a Row tool.
An arrow appears at the beginning of the line.

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Defining inheritances in a CDM

6. Type a specifying attribute name and a specifying attribute code.
7. Click Apply.
You commit the creation of the new attribute.
8. Click the new attribute line.
An arrow appears at the beginning of the line.
9. Click the Properties tool.

or
Double-click the arrow at the beginning of the line.
The attribute property sheet appears.
10. Type or select attribute properties.
11. Click OK.

Modifying the inheritance display preferences
You can modify the following display preference of an inheritance using the
Tools ä Display Preferences command:

122

Preference

Description

Name

Displays the name of the inheritance

Stereotype

Stereotype of the inheritance

Chapter 3. Building Conceptual Data Models

Defining check parameters in a CDM
Check parameters are set of conditions which data must satisfy to remain
valid.
There are three types of check parameters:
Parameter type

Description

Can be attached to

Standard check
parameters

Common data constraints which
define a data range. For example
minimum and maximum values for a
column

Entity attributes

Additional check
parameters

SQL expression defining a data constraint using the %MINMAX%,
%LISTVAL%, and %RULES% variables that are instantiated with standard parameter values

Entity attributes

Validation rule

Business rule that is defined as a
server expression, and is attached to
one of the following listed objects

Entities

Domains

Entity attributes
Domains

Setting standard parameters for objects in a CDM
Standard parameters indicate common data constraints. The following table
lists standard parameters:
Parameter

Description

Minimum

Lowest acceptable numeric value

Maximum

Highest acceptable numeric value

Default

Value assigned in absence of an expressly entered value

Unit

Standard measure

Format

Data format (for example, 9999.99)

Lowercase

Forces all alphabetical characters to lowercase

Uppercase

Forces all alphabetical characters to uppercase

Cannot Modify

Protects from changes, results in a non-modifiable column
in the physical data table

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Defining check parameters in a CDM

Parameter

Description

List of Values

Authorized values

Label

String that identifies an authorized value in the list

v To set standard parameters for objects in a CDM
1. Click the Standard Checks tab in the property sheet of a domain or an
entity attribute to display the corresponding page.

2. Type your choice of Standard Parameters.
3. Click OK.

Defining additional check parameters for objects in a CDM
You can write an SQL statement using the following standard variables
defined as standard check parameters and validation rules:

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Chapter 3. Building Conceptual Data Models

Variable

Description

%MINMAX%,

Minimum and maximum values defined in Values groupbox on Standard Checks page

%LISTVAL%

Customized values defined in List Values groupbox on
Standard Checks page

%RULES%

Validation rule expression defined on Expression page of
the Rules property sheet

You define additional check parameters for data constraints where standard
check parameters are not sufficient.
Example

An entity in a data model for a clothing shop may contain check parameters
defined for an entity attribute SIZE, which depend on the check parameters
defined for another entity attribute COUNTRY, as clothing size for a skirt in
France may be different from the same size in the United States.
In this case an expression is required to create a constraint which uses check
parameters defined for both entity attributes.
v To define additional check parameters for objects
1. Click the Additional Checks tab in the property sheet of a domain or an
entity attribute to display the corresponding page.
2. Type SQL expression using the variables %MINMAX%, %LISTVAL%,
and %RULES%.

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Defining check parameters in a CDM

3. Click OK.

Using a validation rule in check parameters in a CDM
A validation rule is a rule that validates data based on a corresponding
business rule. A validation rule can be generated as a check parameter when
the following conditions apply:
♦ Validation rule is attached to an entity, entity attribute, or domain
♦ Validation rule is defined as a server expression
At generation, validation rule variables are instantiated with the following
values:

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Chapter 3. Building Conceptual Data Models

Variable

Value

%COLUMN%

Code of the column to which the business rule applies

%DOMAIN%

Code of the domain to which the business rule applies

%TABLE%

Code of the table to which the business rule applies

%MINMAX%

Minimum and maximum values for the entity attribute
or domain

%LISTVAL%

List values for the entity attribute or domain

%RULES%

Server validation rules for the entity attribute or domain

+ For more information on defining business rules, see section Defining a
business rule in a CDM in chapter Using Business Rules in a CDM.
v To use a validation rule in check parameters
1. Click the Rules tab in the property sheet of a domain, an entity or an
entity attribute to display the corresponding page.
2. Click the Add Rules tool.
A list appears displaying the available business rules in the model.
3. Select a business rule in the list.
4. Click OK in each of the dialog boxes.
Validation rule expressions

You must click the Rules button to modify the expression attached to a
validation rule. You can also modify validation rule expressions from
the list of business rules, by clicking the Define button.

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CHAPTER 4

Working with Conceptual Data Models
About this chapter

Contents

This chapter describes how to check the validity of a Conceptual Data Model
and how you can import an ERwin model into a CDM. It also gives
information on how you can open a ProcessAnalyst Model (PAM) into a
CDM.
Topic:

page

Checking a CDM

130

Object parameters verified by Check model

136

Opening a PAM into a CDM

151

129

Checking a CDM

Checking a CDM
You can use the Check Model to check the validity of a CDM at any time.
A valid CDM conforms to the following rules:
♦ Each object name must be unique
♦ Each entity must have at least one attribute
♦ Each relationship must be attached to at least one entity

CDM check options
When you check a CDM, you can define levels of severity for problems that
Check model finds and have certain problems automatically corrected.
Levels of problem
severity

You can set a level of problem severity for each object parameter that is
verified by the Check model. This severity level can depend on the degree of
normalization that you want to achieve in a your model.
When you check a CDM, you can display an invalid parameter with one of
two types of messages, depending on the degree of problem severity you
assigned to that parameter:

Automatic correction

Message

Description

Error

Major problem that impedes database generation

Warning

Minor problem or recommendation

You can choose to have certain problems corrected automatically by
PowerDesigner. Automatic correction primarily fixes non-unique names in
the CDM. However, before using automatic correction, make sure you
understand how it will affect your model.

+ As automatic correction is not available for most object parameters, they
must be corrected manually.

+ For more information on manual and automatic correction, see “Object
parameters verified by Check model” on page 136.
Setting problem severity
and automatic correction

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You can use the following tools from the Check Model Parameters dialog
box to set either an error or warning level of problem severity, and also if
you want PowerDesigner to automatically correct an error:

Chapter 4. Working with Conceptual Data Models

Tool

Indicates

Description

Error

Indicates a major problem that impedes database
generation

Warning

Indicates a minor problem or recommendation

Automatic
correction

Indicates that PowerDesigner will correct the
problem automatically

CDM object selection in the Check Model
You select objects to be checked from the Selection page of the Check
Model Parameters dialog box (Tools ä Check Model).
You can list all objects created in the current model, current package, or
sub-packages by selecting the Include Sub-Objects tool.
You have the following selection options:
Parent

Include Sub-Objects se-

Include Sub-Objects not se-

object

lected

Model

All objects created in model
including those in packages
and sub-packages

All objects created in model
except those in packages and
sub-packages

Package

All objects created in package including those in subpackages

All objects created in package
except those in sub-packages

Selecting objects in the diagram

If you graphically select objects in your diagram before starting the Check
Model, they can be automatically selected for verification by the Check
Model by clicking the Use Graphical Selection tool in the Selection page
toolbar.

Checking a global CDM

131

Checking a CDM

v To check a global CDM
1. Select Tools ä Check Model.

or
Right-click the diagram background and select Check Model from the
contextual menu.
The Check Model Parameters dialog box opens to the Options page.
2. Expand an object parameter node.
The object parameters which are verified by the Check Model are
displayed with the symbols indicating a degree of problem severity.

3. If you want to change a degree of problem severity, select the object
parameter and then select either the Error or Warning tool.
The symbol changes to the appropriate severity level.
4. If you want PowerDesigner to automatically correct a problem, select the
object parameter and then select the Automatic Correction tool.
The Automatic Correction symbol appears superimposed on the Error or
Warning symbol for that object parameter.
5. Click the Selection tab to display the corresponding page.
6. Select a model from the dropdown list at the top of the dialog box.

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7. Click an object tab.
The corresponding object page displays all the objects in the current
CDM.

8. Select check boxes for objects that you want to be checked.
Clear check boxes for objects that you do not want to be checked.
Selecting all or clearing all check boxes

You can select all object check boxes by clicking the Select All tool.
You can clear all object check boxes by clicking the Deselect All tool.
9. Click OK.
The Check Model Result List dialog box displays errors and warnings,
based on your choice of check options.

Dockable result window

When you right-click an object parameter a menu appears listing correction
options. Among these, you can also select options to clear, dock or hide
the result window.
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Checking a CDM

Displaying previously applied check options
If you click the Apply button in the Check Model Parameters dialog box, all
error and warning selections are stored in memory.
v To display errors and warnings selected in the last check
1. Select Tools ä Check Model.
The Check Model Parameters dialog box opens to the Options page. The
object parameters are displayed with the Error or Warning icons selected
in the last check.

Making corrections based on CDM check results
You can use the Check Model to locate and correct problems in the CDM.
You can choose one of the following correction options from the Check
toolbar:
Symbol

Option

Description

Manual correction

Displays property sheet of problem object

Display help

Displays description of the error and suggestion for correction

Check again

Checks selected object parameter, normally
after a correction has been done

Automatic correction

Automatically corrects certain errors

Navigating in the error list The Check tool bar also contains navigation tools that you can use to move

to the first, previous, next, or last errors that are listed. You can also navigate
in the list of errors by right-clicking an object parameter and selecting Go To
First error, Previous error, Next error, or Last error from the contextual
menu.
Contextual menu

When you right-click an object parameter in the Result List to open
a contextual menu that lists the following correction options: Correct
(manual correction), Help (error description), Check again, and Automatic
Correction. You can also select options to navigate among errors, clear the
Result List, dock and hide the result window.

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Chapter 4. Working with Conceptual Data Models

Making manual corrections to a CDM
v To make manual corrections to a CDM
1. Select an object parameter from the Result List.
2. Right-click the object parameter and select Correct from the contextual
menu.
The object property sheet appears.
3. Select the appropriate tab and make the necessary correction.
4. Close the property sheet.
5. Re-select the object parameter.
6. Right-click the object parameter and select Check again from the
contextual menu.
Verify that the problem has been corrected.
Making automatic corrections to a CDM
v To make automatic corrections to a CDM
1. Select an object parameter, from the Result List.
2. Right-click the object parameter and select Automatic Correction from
the contextual menu.
3. Right-click the object parameter and select Check again from the
contextual menu.
Verify that the problem has been corrected.

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Object parameters verified by Check model

Object parameters verified by Check model
The Check Model verifies the validity of the following CDM objects.
When errors are encountered during a check model, corrections can be made
manually or automatically. Manual corrections depend on how you are using
your model.
Use the Help command to select object control options

When you right-click a CDM object control in the Check Model Parameters
page, a menu appears listing several options. The Help command opens
a contextual help page explaining the checks performed for the selected
object type.

Business Rule check in a CDM
During a business rule check, the following object controls are made.
Business rule name and code uniqueness
A model cannot contain two business rules with identical name and/or code.
Manual correction

Automatic correction

Modify the duplicated business
rule name/code

Modifies the business rule name/code of
a selected object by appending a number
to its current name

Unused business rule
The business rule you have created is not used in the model.
Manual correction

Automatic correction

Apply the business rule to an
object in the model

—

Package check
During a package check, the following object controls are made.
Circular dependency
A circular dependency occurs when an entity depends on another and so on
until a dependency loop is created between entities. A package cannot
contain circular dependencies.

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Chapter 4. Working with Conceptual Data Models

Manual correction

Automatic correction

Clear the Dependent check box
for the link or delete an inheritance link

—

Circularity with mandatory links
A circular dependency occurs when an entity depends on another and so on
until a dependency loop is created between entities through mandatory links.
Manual correction

Automatic correction

Clear the Mandatory parent
check box or delete a dependency on a relationship

—

Shortcut code uniqueness
Two shortcuts with the same code cannot be in the same namespace.
Manual correction

Automatic correction

Change the code of one of the
shortcuts

—

Shortcut potentially generated as child table of a reference
The package should not contain associations or relationships with an
external shortcut as child entity. Although this can be tolerated in the CDM,
the association or relationship will not be generated in a PDM if the external
shortcut is generated as a shortcut.
Manual correction

Automatic correction

Modify the design of your model
in order to create the association or
relationship in the package where
the child entity is defined

—

Domain check
During a domain check, the following object controls are made.

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Object parameters verified by Check model

Domain name and code uniqueness
Domain names and codes cannot be used more than once in the model.
Manual correction

Automatic correction

Modify the duplicate domain
name/code

Modifies the domain name/code of a
selected object by appending a number
to its current name

Inconsistency in check parameters
The values entered in the check parameters page are inconsistent for numeric
and string data types: default does not respect minimum and maximum
values, or default does not belong to list of values, or values in list are not
included in minimum and maximum values, or minimum is greater than
maximum value. Check parameters must be defined consistently.
Manual correction

Automatic correction

Modify default, minimum, maximum or list of values in the check
parameters page

—

Data type precision and length
The data type precision should not be greater than or equal to the length.
Manual correction

Automatic correction

Make the data type length greater
than or equal to the precision

—

Undefined data type
Undefined data types for domains exist. To be complete, a model should
have all its domain data types defined.

138

Manual correction

Automatic correction

While undefined data types are
tolerated, you must select data
types for currently undefined data
types before you can generate a
PDM

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Chapter 4. Working with Conceptual Data Models

Non-valid data type
Invalid data types for domains exist. To be complete, a model should have
all its domain data types correctly defined.
Manual correction

Automatic correction

While tolerated, you must select
valid data types for currently
non-valid data types to generate
the PDM

—

Data item check
During a data item check, the following object controls are made.
Data item name and code uniqueness
Data item names and codes cannot be used more than once in the namespace.
Manual correction

Automatic correction

Modify the duplicate data item
name/code

Modifies the data item name/code of a
selected object by appending a number
to its current name

Unused data items
There are unused data items. These are useless for PDM generation.
Manual correction

Automatic correction

To use a data item, add it to an
entity. If you do not need an
unused data item, delete it to
allow PDM generation

—

Re-used data items
There are entities using the same data items. This can be tolerated if you
defined this check as a warning.

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Object parameters verified by Check model

Manual correction

Automatic correction

Take care to ensure consistency
when defining data item properties

—

Data item and domain divergence
There is a divergence between data items and associated domains. This can
be tolerated if you defined this check as a warning.
Manual correction

Automatic correction

Ensure consistency when defining data item properties

Restores divergent attributes from domain to data items (domain values overwrite data item values)

Automatic correction

Modify default, minimum, maximum or list of values in the check
parameters page

—

Data type precision and length
The data type precision should not be greater than or equal to the length.
Manual correction

Automatic correction

Make the data type length greater
than or equal to the precision

—

Undefined data type
Undefined data types for data items exist. To be complete, a model should
have all its data items data types defined.

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Chapter 4. Working with Conceptual Data Models

Manual correction

Automatic correction

While undefined data types are
tolerated, you must select data
types for currently undefined data
types before you can generate a
PDM

—

Non-valid data type
Invalid data types for data items exist. To be complete, a model should have
all its data types for data items correctly defined.
Manual correction

Automatic correction

While tolerated, you must select
valid data types for currently
non-valid data types to generate
the PDM

—

Entity check
During an entity check, the following object controls are made.
Entity name and code uniqueness
Entity names and codes cannot be used more than once in the namespace.
Manual correction

Automatic correction

Modify the duplicate entity
name/code

Modifies the entity name/code of a selected object by appending a number to
its current name

Entity name and code length
The entity name and code length are limited to a maximum length of 254
characters specified in the naming conventions of the model options.
Manual correction

Automatic correction

Modify the entity name/code
length to meet this requirement

Truncates the entity name/code length
to the maximum length specified in the
naming conventions

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Object parameters verified by Check model

Existence of attributes
An entity must always contain at least one attribute.
Manual correction

Automatic correction

Add an attribute to the entity or
delete the entity

—

Number of serial types greater than 1
An entity cannot have more than one serial type attribute. Serial types are
automatically calculated values.
Manual correction

Automatic correction

Change the types of the appropriate entity attributes to have only
one serial type attribute

—

Existence of identifiers
An entity must contain at least one identifier.
Manual correction

Automatic correction

Add an identifier to the entity or
delete the entity

—

Existence of relationship or association link
An entity must have at least one relationship or association link.
Manual correction

Automatic correction

Add a relationship or an association link to the entity or delete
the entity

—

Redundant inheritance
An entity inherits from another entity more than once. This is redundant and
adds nothing to the model.

142

Manual correction

Automatic correction

Delete redundant inheritances

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Chapter 4. Working with Conceptual Data Models

Multiple inheritance
An entity has multiple inheritance. This is unusual but can be tolerated if
you defined this check as a warning.
Manual correction

Automatic correction

Make sure that the multiple inheritance is necessary in your
model

—

Parent of several inheritances
An entity is the parent of multiple inheritances. This is unusual but can be
tolerated if you defined this check as a warning.
Manual correction

Automatic correction

Verify if the multiple inheritances
could not be merged

—

Entity attribute check
During an entity attribute check, the following object controls are made.
Entity attribute name and code uniqueness
Attribute names and codes cannot be used more than once in the entity.
Manual correction

Automatic correction

Modify the duplicate entity attribute name/code

Modifies the entity attribute name/code
of a selected object by appending a
number to its current name

Entity identifier check
During an entity identifier check, the following object controls are made.
Entity identifier name and code uniqueness
Entity identifier names and codes cannot be used more than once in the
namespace.

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Object parameters verified by Check model

Manual correction

Automatic correction

Modify duplicate entity identifier
names and codes

Modifies the entity identifier name/code
of a selected object by appending a
number to its current name

Existence of an attribute
At least one attribute must exist for an entity identifier.
Manual correction

Automatic correction

Add an attribute to the entity
identifier or delete the identifier

—

Identifier inclusion
An identifier cannot include another one.
Manual correction

Automatic correction

Delete the identifier that includes
an existing identifier

—

Relationship check
During a relationship check, the following object controls are made.
Relationship name and code uniqueness
Relationship names and codes cannot be used more than once in the model.
Manual correction

Automatic correction

Modify the duplicate relationship
name/code

Modifies the relationship name/code of
a selected object by appending a number
to its current name

Reflexive dependency
A dependency means that one entity is defined through a relationship with
another. A dependent relationship cannot therefore be reflexive.

144

Manual correction

Automatic correction

Change or delete the reflexive
dependency

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Chapter 4. Working with Conceptual Data Models

Reflexive mandatory relationship
A reflexive mandatory relationship exists.
Manual correction

Automatic correction

Deselect the Mandatory check
boxes for the relationship to be
non-mandatory

—

Bijective relationship between two entities
There is a bijective relationship between two entities when there is a
two-way one to one relationship between the entities. This is equivalent to a
merge of two entities.
Manual correction

Automatic correction

Merge the entities or modify the
relationship

—

Name uniqueness constraint for many to many relationships and entities
A many-to-many relationship and an entity cannot have the same name or
code.
Manual correction

Automatic correction

Change the name or code of the
many-to-many relationship or the
name or code of the entity. If
you do not, PDM generation will
rename the generated table

—

Consistency between dominant and dependent relationships
A dependent relationship between entities cannot also be a dominant
relationship.
Manual correction

Automatic correction

Select the Dominant check box
on the other (correct) side of the
relationship

—

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Object parameters verified by Check model

Association check
During an association check, the following object controls are made.
Association name and code uniqueness
Association names and codes cannot be used more than once in the
namespace.
Manual correction

Automatic correction

Modify the duplicate association
name/code

Modifies the association name/code of a
selected object by appending a number
to its current name

Association has at least two links
An association is isolated and therefore does not define a relationship
between entities.
Manual correction

Automatic correction

Define at least two links between
the isolated association and one
or several entities

—

Association has two links with identifier link
An identifier link introduces a dependency between two entities. An
association with this type of link must be binary.
Manual correction

Automatic correction

Delete the unnecessary links or
clear the Identifier check box for
a link

—

Association has no more than one identifier link
An identifier link introduces a dependency between two entities. There can
only be one identifier link between two entities otherwise a circular
dependency is created.

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Chapter 4. Working with Conceptual Data Models

Manual correction

Automatic correction

Clear the Identifier check box for
one of the links

—

Absence of properties with identifier links
An association with an identifier link cannot have any properties.
Manual correction

Automatic correction

Move the association properties
into the dependent entity (the one
linked to the association with an
identifier link)

—

Bijective association between two entities
There are bijective associations between two entities when a two-way one to
one association between the entities exist. This is equivalent to a merge of
two entities.
Manual correction

Automatic correction

Merge the entities or modify the
cardinality links

—

Maximum cardinality links
An association with more than two links can only have links with a
maximum cardinality greater than one.
Manual correction

Automatic correction

Change the maximum cardinality
of such links to be greater than 1

—

Reflexive identifier links
An identifier link introduces a dependency between two entities. An
association with this type of link cannot therefore be reflexive.
Manual correction

Automatic correction

Change the relationship between
the entities or clear the Identifier
check box for a link

—

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Object parameters verified by Check model

Name unicity constraint between many-to-many associations and entities
A many-to-many association and an entity cannot have the same name or
code.
Manual correction

Automatic correction

Change the name or code of the
many-to-many association or the
name or code of the entity. If
you do not, PDM generation will
rename the generated table

—

Inheritance check
During an inheritance check, the following object controls are made.
Inheritance name and code uniqueness
Inheritance names and codes cannot be used more than once in the model.
Manual correction

Automatic correction

Modify the duplicate inheritance
name/code

Modifies the inheritance name/code of a
selected object by appending a number
to its current name

Existence of inheritance link
An inheritance must have at least one inheritance link, from the inheritance
to the parent entity.
Manual correction

Automatic correction

Define the inheritance link or
delete the inheritance

—

File object check
During a file object check, the following object controls are made.
Embedded file name uniqueness
You cannot have two embedded file objects with the same name in a model.

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Chapter 4. Working with Conceptual Data Models

Manual correction

Automatic correction

Rename one of the embedded
file objects

Renames the file object by appending a
number to its name

Existence of external file location
External file objects must have a valid location path.
Manual correction

Automatic correction

Define a valid path location

—

Replication check
During a replication check, the following object controls are made.
Partial replication
A replica object is partially synchronized with its replicated object.
Manual correction

Automatic correction

Modify the list of replicated
attributes from the replication
property sheet

Enforces the replication of desynchronized attributes of the replica object in
the replication property sheet

Extended object check
During an extended object check, the following object controls are made.
Extended object name and code uniqueness
Extended object names and codes must be unique in the namespace.
Manual correction

Automatic correction

Modify the duplicate extended object name/code

Modifies the extended object name or
code of a selected object by appending
a number to its current name or code

Extended link check
During an extended link check, the following object controls are made.

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Object parameters verified by Check model

Extended link name and code uniqueness
Extended link names and codes must be unique in the namespace.

150

Manual correction

Automatic correction

Modify the duplicate extended link
name/code

Modifies the extended link name or
code of a selected object by appending
a number to its current name or code

Chapter 4. Working with Conceptual Data Models

Opening a PAM into a CDM
You can recover process model information into a conceptual model by
opening a PAM into a CDM.
You will then retrieve PAM objects into your CDM.

The open process translates PAM objects into CDM objects as follows:
Object in a PAM

Imported object in a CDM

Business rule

Domain

Data store

Entity

Data item

When opening a PAM, you are asked to choose between opening into a BPM
or opening into a CDM knowing that opening a PAM into a BPM allows you
to recover processes.

+ For more information on opening a PAM into a BPM, see the BPM
User’s Guide .
v To open a PAM into a CDM
1. Select File ä Open.
An open file dialog box appears.
2. Select or browse to the folder that contains the PAM file.
3. Select ProcessAnalyst Model (*.pam) file from the Files As Type
dropdown list box to display only PAM files.
The available PAM files are listed.
4. Select a file.
5. Click Open.
The Formats for ProcessAnalyst Model window appears.

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Opening a PAM into a CDM

6. Select PowerDesigner Conceptual Data Model and click OK.

The Output window displays a message following the successful import
and the default diagram of the model appears. Each imported object type
can be viewed from its respective list.

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CHAPTER 5

Generating from a Conceptual Data Model
About this chapter
Contents

This chapter describes how you can generate a CDM, a PDM, and an OOM
from a Conceptual Data Model.
Topic:

page

Generation basics

154

Generating a Conceptual Data Model from a Conceptual Data
Model

155

Generating a Physical Data Model from a Conceptual Data Model

157

Generating an Object Oriented Model from a Conceptual Data
Model

171

153

Generation basics

Generation basics
You can generate a CDM, a PDM, or an OOM from a CDM.

+ For more information on model to model or inter-model generation
common features, see the “Linking and Synchronizing Models in
PowerDesigner” chapter in the General Features Guide .

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Chapter 5. Generating from a Conceptual Data Model

Generating a Conceptual Data Model from a
Conceptual Data Model
This section explains how to generate a Conceptual Data Model from a
Conceptual Data Model.

Why generate a CDM into a CDM?
You can generate a CDM into a CDM when you need to keep two models
synchronized during the design process.
This kind of generation allows you to create a copy of a given model and
define generation links between objects in the source CDM and their
equivalent in the generated CDM. When changes are made to the source
model, they can then be easily propagated to the generated models using the
Update Existing Model generation mode.
The generated model is the one that usually contains more information.

Generating and updating a CDM
To generate a CDM, you must choose between one of the following
methods:
♦ Generate new Conceptual Data Model
♦ Update existing Conceptual Data Model
You must indicate the following parameters when you generate a new CDM:
Parameter

Description

Name

File name for the resulting CDM

Code

Reference code for the resulting CDM

Configure
Model Options

Lets you define the model options for the new CDM

+ For more information, see the “Linking and Synchronizing Models in
PowerDesigner” chapter in the General Features Guide .

Defining CDM generation options
You can set the following general generation options:

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Generating a Conceptual Data Model from a Conceptual Data Model

Option

Description

Check Model

When selected, verifies the model before generating the
CDM, and stops generation if an error is found

Save Generation Dependencies

When selected, PowerDesigner keeps track of the identity
of the origin of each generated object. It is useful when
merging two CDM which have been generated from the
same CDM. Objects can be compared and recognized as
the same object, even if the object has been modified in
the merged CDM. If not selected, origin objects have no
link with generated objects

Enable transformations

This button is used to activate transformations during
generation.
When you click this button, the Pre-generation tab appears
if the source model contains transformations. You can
select the transformations to execute before generation.
The Extended Model Definitions tab also appears for you
to select extended model definition files to attach to the
generated model. These files may contain post-generation
transformations, in this case, the Post-Generation tab
appears to let you select the transformations you want
to be executed in the generated model. If the generation
is an update, and the generated model contains extended
model definitions with post-generation transformations,
the Post-generation tab automatically appears as soon as
you click the Enable Transformations button

Check model before generation

If you select the Check Model option, the procedure to generate a CDM
starts by checking the validity of the CDM . A CDM results when no errors
are found. You can set check options by selecting Tools ä Check Model.

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Chapter 5. Generating from a Conceptual Data Model

Generating a Physical Data Model from a
Conceptual Data Model
This section explains how to generate a Physical Data Model from a
Conceptual Data Model.

Generating PDM objects
When you generate a physical data model (PDM) from a CDM,
PowerDesigner converts CDM objects and data types to PDM objects and
data types supported by the current DBMS.
Converting CDM to PDM objects
PDM generation converts conceptual objects into physical objects as
follows:
CDM objects

Generated object in a PDM

Entity

Table

Entity attribute

Table column

Primary identifier

Primary or foreign key depending on independent or
dependent relationship

Identifier

Alternate key

Relationship

Reference

Changing the name of a column automatically

Two columns in the same table cannot have the same name. If column
names conflict due to foreign key migration, PowerDesigner automatically
renames the migrated columns. The new name is composed of the first
three letters of the original entity name followed by the code of the attribute.
Generating keys from identifiers
Primary identifiers generate primary and foreign keys in the PDM.
Identifiers that are not primary identifiers generate alternate keys.
The type of key that is generated in the PDM depends on the cardinality and
type of dependency defined for a relationship in the CDM.
A primary key is a column or columns whose values uniquely identify a
row in a table.

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Generating a Physical Data Model from a Conceptual Data Model

A foreign key is a column or columns that depend on and migrate from a
primary key column in another table.
An alternate key is a column or columns whose values uniquely identify a
row in a table, and is not a primary key.
Independent
one-to-many
relationships

In independent one-to-many relationships, the primary identifier of the entity
on the one side of the relationship becomes a:
♦ Primary key in the table generated by the entity on the one side of the
relationship
♦ Foreign key in the table generated by the entity on the many side of the
relationship
The CDM below shows an independent relationship. Each division contains
one or more employees:

The CDM above generates two tables:
Table

Primary key

Foreign key

Division

Division number

—

Employee

Employee number

Division number

The following PDM results from generation:

Dependent one-to-many
relationships

In dependent relationships, the primary identifier of the nondependent entity
becomes a primary/foreign key in the table generated by the dependent
entity.
The migrated column is integrated into the primary key if it already exists.
The CDM below shows a dependent relationship. Each task must have a
project number.

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Chapter 5. Generating from a Conceptual Data Model

The CDM above generates two tables:
Table

Primary key

Foreign key

Project

Project number

—

Task

Project number/Task number

Project number

The following PDM results from generation.

Independent
many-to-many
relationships

In independent many-to-many relationships, the primary identifiers of both
entities migrate to a join table as primary/foreign keys. The CDM below
shows an independent relationship. Each employee can be a member of one
or more teams, and each team can have one or more employees as members.

Table

Primary key

Foreign key

Team

Team number

—

Employee

Employee number

—

Member

Team number/Employee number

The following PDM results from generation.

Independent one-to-one
relationships

In independent one-to-one relationships, the primary identifier of one entity
migrates to the other generated table as a foreign key.

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Generating a Physical Data Model from a Conceptual Data Model

Generating tables from entities with inheritance links
Two properties influence the generation of tables from entities with
inheritance links.
Object

Property

When selected generates

Entity

Generate table

Table for the entity (parent or child)

Inheritance

Generation mode

Parent and/or children as indicated

Converting CDM to PDM data types
PowerDesigner supports both conceptual and physical data types. Data types
that you select in the CDM are not always supported by the current DBMS.
In this case, the data type is converted to a data type supported by the current
DBMS when you generate the PDM.
Accessing the DBMS to define data type conversions
Each DBMS contains rules for data type conversion.
The correspondence between the PowerDesigner data type and the physical
data type for the current DBMS is listed under the Data Type node, under the
Script node in the DBMS tree view.

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The Physical Model column lists the data types for the current DBMS and
the Internal column lists the PowerDesigner equivalent. You can modify the
definition of an existing physical data type by making modifications directly
to either of the two columns.
Modifying the DBMS

You should only modify a copy of the DBMS shipped with PowerDesigner.
Once a modification has been committed in the DBMS you cannot return
to the default value for the data type.

+ For more information on modifying a DBMS, see chapter DBMS Basics
in the Physical Data Model User’s Guide.
v To access a DBMS
1. Select Tools ä Resources ä DBMS to display the List of DBMS.
2. Select a DBMS from the list.
Click the Properties tool.

or
Double-click a DBMS name in the list.
The DBMS property sheet appears.
3. From the General page, expand the Script node, then expand the Data
Type node.
4. Select the item PhysDataType.
The values for the DBMS data types and the corresponding
PowerDesigner data types appear in the Value pane to the left of the tree
view.
5. Click OK.
Converting conceptual data types
The following table lists the conceptual data types to which the DBMS
assigns conversions:
Numeric data types
Conceptual
data type

Code in
DBMS

What it stores

Conversion example
for SQL Anywhere

Integer

32-bit integer

integer

Short Integer

16-bit integer

smallint

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Generating a Physical Data Model from a Conceptual Data Model

Character data types

162

Conceptual
data type

Code in
DBMS

What it stores

Conversion example
for SQL Anywhere

Long Integer

32-bit integer

integer

Byte

256 values

smallint

Number

Numbers with a fixed
decimal point

numeric

Decimal

Numbers with a fixed
decimal point

decimal

Float

32-bit floating point
decimal numbers

float

Short Float

Less than 32-bit floating point decimal number

real

Long Float

64-bit floating point
decimal numbers

double

Money

Numbers with a fixed
decimal point

numeric

Serial

Automatically incremented numbers

numeric

Boolean

Two opposing values
(true/false; yes/no;
1/0)

numeric(1)

Chapter 5. Generating from a Conceptual Data Model

Conceptual
data type

DBMS

What it stores

Conversion example for
SQL Anywhere

Characters

Character strings

char

Variable
Characters

Character strings

varchar

Long Characters

Character strings

varchar

Long Var
Characters

LVA

Character strings

long varchar

Text

TXT

Character strings

long varchar

Multibyte

Multibyte character strings

char

Variable
Multibyte

VMB

Multibyte character strings

varchar

Conceptual
data type

DBMS

What it stores

Conversion example
for SQL Anywhere

Date

Day, month, year

date

Time

Hour, minute, and
second

time

Date & Time

Date and time

timestamp

Timestamp

System date and time

timestamp

Time data types

Other data types

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Generating a Physical Data Model from a Conceptual Data Model

Conceptual
data type

DBMS

What it stores

Conversion example
for SQL Anywhere

Binary

BIN

Binary strings

binary

Long Binary

LBIN

Binary strings

long binary

Image

PIC

Images

long binary

Bitmap

BMP

Images in bitmap
format (BMP)

long binary

OLE

OLE links

long binary

Other

User-defined data
type

char(10)

Not yet defined data
type

Undefined

Generating and updating a PDM
To generate a PDM, you must choose between one of the following methods:
♦ Generate new Physical Data Model
♦ Update existing Physical data Model
You must indicate the following parameters when you generate a new PDM:
Parameter

Description

DBMS

Database Management System definition (DBMS) for the
resulting PDM

The resulting PDM uses a shared DBMS definition file
stored in the DBMS library

Copy

The resulting PDM uses a copy of the DBMS definition
file stored in the model

Name

File name for the resulting PDM

Code

Reference code for the resulting PDM

Configure
Model Options

Lets you define the model options for the new PDM

+ For more information, see the “Linking and Synchronizing Models in
PowerDesigner” chapter in the General Features Guide .

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Chapter 5. Generating from a Conceptual Data Model

Configuring the generated PDM options
When you configure the options of a PDM to generate, you may define
options diverging from the CDM options.
To avoid conflicts, PowerDesigner applies the following rule for default
values of PDM options: an option defined for the generated PDM should
respect the equivalent option of the CDM.
Equivalent options are model options found in both models. The Enforce
non-divergence option exists in both CDM and PDM.

References unique code

CDM option

PDM option

Result in generated PDM

4 Enforce nondivergence

—

Enforce non-divergence in model according to CDM options. Columns
attached to the domain cannot have
divergent definitions

—

4 Enforce nondivergence

Enforce non-divergence in model according to PDM options defined using
the Configure Model Options feature

Unique Code for references is not selected by default in the PDM options.
However, if you select Unique Code for references in the PDM options,
relationships are renamed during the generation of a CDM to a PDM.
Options with no equivalent, like Use Data Type Full Name in the CDM
without any corresponding option in a PDM, are generated using default
values found in the registry.

Defining PDM generation options
You can set the following general generation options from the Detail page:

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Generating a Physical Data Model from a Conceptual Data Model

Option

Description

Check Model

When selected, checks the model before generating the
PDM, and stops generation if an error is found

Save Generation Dependencies

When selected, PowerDesigner keeps track of the identity
of the origin of each generated object. This is useful when
merging two PDM which have been generated from the
same CDM. Objects can be compared and recognized as
the same object, even if the object has been modified in
the target PDM. If not selected, origin objects have no link
with generated objects

Convert Names
into Codes

When selected, object codes are generated from names
using the corresponding conversion script. This is useful
when generating models with very different naming conventions . For example a Java class attribute code may be
“customerName” whereas a PDM table column code may
be “CUSTOMER_NAME”. With this option selected,
both objects will have their codes generated from their
names. If you do not select this option, generated object
codes will be copied from original object codes

Rebuild Triggers

When selected, allows to build triggers with preservation
option, after the PDM generation. Rebuild takes place
after merge if you are updating an existing PDM

Enable transformations

+ For more information conversion scripts, see section Using a conversion
script in chapter Managing models in the General Features Guide .

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Chapter 5. Generating from a Conceptual Data Model

Check model before generation

If you select the Check Model option, the procedure to generate a PDM
starts by checking the validity of the CDM . A PDM results when no errors
are found. You can set check options by selecting Tools ä Check Model.
Table parameters

Reference parameters

Foreign key name

The following parameter defines the naming convention for tables:
Parameter

Description

Table Prefix

Prefix for the names of tables generated from entities in the
CDM

The following parameters define default referential integrity constraints:
Parameter

Description

Update Rule

Default update constraint for referential integrity

Delete Rule

Default delete constraint for referential integrity

By default, the name of the migrated foreign keys generated in a PDM is
identical to the name of the primary key. In case of column name conflict,
the first 3 letters of the name of the parent table are added before the name of
the migrated column.
You can modify this default behavior and use templates for naming the
migrated foreign keys. In the Reference groupbox, you can select one of the
predefined templates in the FK Column Name Template dropdown listbox.
These templates are saved in the registry, you can modify them, but their
default value is preserved.
You can also create your own foreign key naming templates by typing a
template directly in the FK Column Name Template box using the following
variables:

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Generating a Physical Data Model from a Conceptual Data Model

Variable

Value

%REFR%

Name / Code of the reference

%PARENT%

Name / Code of the parent table

%COLUMN%

Name / Code of the parent column

%KEY%

Name / Code of the key constraint attached to the
reference

%CONSTNAME%

Name of the key constraint attached to the reference
(same as %KEY%)

%PROLE%

Role of the entity that generated the parent table, this
variable proceeds from the conceptual environment.
If no role is defined on the relationship or association,
%PROLE% takes the content of %PARENT% to
avoid generating a column with no name

You can use the default PowerDesigner formatting variables in the template
as explained in section List of PowerDesigner formatting variables in
chapter Variables in PowerDesigner in the PDM User’s Guide .
You can also use square brackets [ ] for evaluating optional variables as
explained in “Optional strings and variables” in the “DBMS Reference
Guide” chapter in the Advanced User Documentation .
Customized naming templates reappear in the generation dialog box the next
time you open it, but are not saved in the registry thus not added to the
dropdown list of predefined templates.
For example, if you define the template %PROLE%, the name of the foreign
key will be made of the role beside the entity that generated the parent table
containing the primary key. If the parent table contains multiple keys, the
foreign key names will be automatically renamed.
Other example:
[%PROLE%=%PARENT%?%.3:PARENT%_%COLUMN%:%PROLE%]

This checks the %PROLE% value; if it is equal to the parent name (which is
the replacement value) then the template “%.3:PARENT%_%COLUMN%”
will be used, otherwise template “%PROLE%” will be used because the user
has entered a parent role for the relationship.
In the Reference groupbox, you can select the Always Use Template radio
button to always use the default or customized template for naming FK

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Chapter 5. Generating from a Conceptual Data Model

columns, even if there is no conflict with an existing column.
Index parameters

The following parameters define naming conventions for indexes:
Parameter

Description

PK index names

Naming convention for primary keys, by default
%TABLE%_PK

Key index names

Naming convention for alternate keys, by default
%TABLE%_AK

FK index names

Naming convention for foreign keys, by default
%REFR%_FK

FK threshold

Minimum number of estimated occurrences of an entity
necessary to create an index on a foreign key

If you enter a value for the index threshold, indexes on foreign keys are only
generated if the number of estimated occurrences is greater than the
threshold. The estimated number of occurrences is an entity property that
you can include in the entity definition.
If the entity has no specified number of occurrences, the foreign key indexes
are generated by default.
PK index name variables

FK index name variables

You can use the following variables in the PK index names and Key Index
Names fields:
Variable

Value

%TABLE%

Generated code of the table. This is the table code that is
generated in the database. It may or may not be truncated
if the code contains characters not supported by the
DBMS

%TNAME%

Table name

%TCODE%

Table code

%TLABL%

Table comment

You can use the following variables in the FK index name field. The
generated code of a variable is the code defined in the object property sheet,
but which may or may not be truncated when generated if the code contains
characters not supported by the DBMS
Variable

Value

%REFR%

Generated code of the reference

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Generating a Physical Data Model from a Conceptual Data Model

Variable

Value

%REFNAME%

Reference name

%REFRCODE%

Reference code

%PARENT%

Generated code of the parent table

%PNAME%

Parent table name

%PCODE%

Parent table code

%CHILD%

Generated code of the child

%CNAME%

Child table name

%CCODE%

Child table code

%PQUALIFIER%

Parent table qualifier

%CQUALIFIER%

Child table qualifier

Preserving a modified primary key

If you modify a primary key in a PDM, then regenerate the PDM from a
CDM, the modified primary key is not preserved. If you want to preserve a
modified primary key, you need to modify the identifier in the CDM before
regeneration.

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Generating an Object Oriented Model from a
Conceptual Data Model
This section explains how to generate an Object Oriented Model from a
Conceptual Data Model.

Generating OOM Objects
When you generate an Object Oriented Model (OOM) from a CDM,
PowerDesigner converts CDM objects into specified object language objects
as follows:

Persistent entities

CDM Objects

Generated object in an OOM

Entity

Class

Attribute

Association

Relationship or association

Binary association with attributes

Association class

Inheritance

Generalization

All entities are generated as persistent classes with the “Generate table”
persistence mode.
When the Generate check box of an entity is not selected, the generated class
has the “Migrate columns” persistence mode.
OOM naming conventions

If the code of the generated OOM objects does not correspond to the target
language naming conventions, you can define a code naming convention
script to convert object names into codes. For more information on
conversion scripts, see section .convert_name & .convert_code macros in
chapter Managing Models in the General Features Guide.

Converting CDM to OOM data types
PowerDesigner supports both conceptual and object language data types.
The following table lists the conceptual data types to which the object
language definition assigns conversions:

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Generating an Object Oriented Model from a Conceptual Data Model

Conceptual
data type

Code in
CDM

What it stores

Conversion example with Java

Characters

Character strings

Char

Boolean

Two opposing values
(true/false; yes/no; 1/0)

Boolean

Byte

256 values

Byte

Short Integer

16-bit integer

Short

Long Integer

32 bit integer

Long integer

Integer

32 bit integer

Integer

Float

32 floating decimal numbers

Float

Number

Numbers with a fixed decimal point

Double

Text

TXT

Character strings

Generating and updating an OOM
To generate an OOM, you must choose between one of the following
methods:
♦ Generate new Object-Oriented Model
♦ Update existing Object-Oriented Model
You must indicate the following parameters when you generate a new OOM:

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Chapter 5. Generating from a Conceptual Data Model

Parameter

Description

Object Language

Target object language

Object language for the resulting OOM uses a shared
Object language definition file stored in the Object
language library

Copy

Object language for the resulting OOM uses a copy of
the Object language definition file stored in the Object
language library

Name

File name for the resulting OOM

Code

Reference code for the resulting OOM

Configure Model
Options

Lets you define the model options for the new OOM,
you can select the naming conventions corresponding
to the target language for example

+ For more information, see the “Linking and Synchronizing Models in
PowerDesigner” chapter in the General Features Guide .
Configuring the generated OOM options
When you configure the options of an OOM to generate, you may define
options diverging from the CDM options.
To avoid conflicts, PowerDesigner applies the following rule for default
values of OOM options: an option defined for the generated OOM should
respect the equivalent option of the CDM.
Equivalent options are model options found in both models. The Enforce
non-divergence option exists in both CDM and OOM.
CDM option

OOM option

Result in generated OOM

4 Enforce nondivergence

—

Enforce non-divergence in model according to CDM options

—

4 Enforce nondivergence

Enforce non-divergence in model according to OOM options defined using
the Configure Model Options feature

Options with no equivalent, like Use Data Type Full Name in the CDM
without any corresponding option in an OOM, are generated using default
values found in the registry.

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Generating an Object Oriented Model from a Conceptual Data Model

Defining OOM generation options
You can set the following general generation options from the Detail page:
Option

Description

Check Model

When selected, checks the model before generating the
OOM, and stops generation if an error is found

Save Generation Dependencies

When selected, PowerDesigner keeps track of the identity
of the origin of each generated object. It is useful when
merging two OOM which have been generated from the
same CDM. Objects can be compared and recognized as
the same object, even if the object has been modified in the
target OOM. If not selected, origin objects have no link
with generated objects

Convert Names
into Codes

When selected, object codes are generated from names
using the corresponding conversion script. This is useful when generating models with very different naming
conventions since conversion macros are used to modify
codes. For example a Java class attribute code may be
“customerName” whereas a PDM table column may be
“CUSTOMER_NAME”. With this option selected, both
objects will have their codes generated from their names.
If you do not select this option, generated object codes
will be copied from original object codes

Enable transformations

Class Prefix

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Prefix for a class. It can help identify a class in a model

Chapter 5. Generating from a Conceptual Data Model

+ For more information conversion scripts, see section Using a conversion
script in chapter Managing models in the General Features Guide .
Check model before generation

If you select the Check Model option, the procedure to generate an OOM
starts by checking the validity of the CDM . An OOM results when no
errors are found. You can set check options by selecting Tools ä Check
Model.

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CDM Glossary
association

In the Merise modeling methodology an association is a connection between
entities

business rule

Written statement specifying what the information system must do or how it
must be structured to support business needs

column

Data structure that contains an individual data item within a row in a PDM

Conceptual Data Model
(CDM)

Entity-relationship diagram that models the information system without
considering the details of physical implementation

constraint

Named check that enforces data requirements, default values, or referential
integrity on an entity or a entity attribute

data item

Elementary piece of information

domain

Set of values for which a data item is valid

entity

Person, place, thing, or concept that has characteristics of interest to the
enterprise and about which you want to store information

entity attribute

Elementary piece of information attached to an entity

foreign key

Column or columns in a PDM whose values depend on and migrate from a
primary key, or an alternate key, in another table

Identifier

Entity attribute, or a combination of entity attributes, whose values uniquely
identify each occurrence of the entity

Inheritance

Special relationship that defines an entity as a special case of a more general
entity

Object-Oriented Model
(OOM)

Structure that is the logical design view of a software system. An OOM is a
conceptual model of a software system

Physical Data Model
(PDM)

Table-reference diagram that models the information system including the
details of physical implementation

primary key

Column or columns whose values uniquely identify a row in a table in PDM

property sheet

Window that displays the properties of an object

reference

Link between a parent table and a child table in a PDM. A reference can link

177

tables by shared keys or by specified columns
referential integrity

Rules governing data consistency, specifically the relationships among
primary keys and foreign keys of different tables in a PDM

relationship

Named connection or association between entities

stereotype

Sub-classification used to extend the semantics of an object without
changing its structure; it can be predefined or user-defined

table

Collection of rows (records) in a PDM that have associated columns (fields)

178

Index
A
All Objects option
association (CDM)
cardinality
change to entity
check model
create from Browser
create from diagram
create from list
define
dependent
display preferences
entity
entity attribute
properties
reflexive
validity check
association attribute (CDM)
create
create from list
list
validity check
association link
cardinality
create from diagram
create from list
define
display preferences
drag
properties
symbol
attribute (CDM)
association
enforce coherence

5
3
101
104
146
97
97
97
95, 104
103
108
104
104
96
100
136
105
107
105
136
101
98
98, 99
96
109
98
96
98
3
105
10

B
bibliography
binary data type
bitmap data type
boolean data type
business rule (CDM)

vii
46, 163
46, 163
44, 161
22, 23

apply
check model
create
definition
domain (CDM)
expression
fact
formula
properties
requirement
type
validation
validation rule
byte data type

27, 126
136
24
23
50
26, 126
23
23
23
23
23
23
126
44, 161

C
cardinality
association (CDM)
change format
change from the registry
define
define for an association link
many to many
many to one
one to many
one to one
relationship
CDM
check
check options
check results
close
correct
create
data type
define
detach from workspace
domain
enable transformations
enforce domain
Entity Relationship Diagram
ERD

101
101
101
80
101
80
80
80
80
80, 91
130, 131, 135
130
134
17
134, 135
14
161
2, 13
17
40
155
4
2
2

179

Index

error
36, 79, 130, 131, 134, 135
extended dependency
12
extended model definition
11
generate
154, 155
generation option
155
generation parameter
155
logical model
2
modify properties
13
object
3, 157, 171
open
16
open PAM
151
option
11, 35, 79
package
18
role
2
save
17
validate
130
warning
130, 131, 134, 135
CDM environment
4
Change to Entity Wizard
89
check model
association (CDM) check
146
automatic correction
130
business rule (CDM)
136
CDM
130, 131, 135
correct
134, 135
data item check
139
domain check
137
entity attribute check
143
entity check
141
entity identifier check
143
error severity
130
extended link
149
extended object
149
file object
148
global model
131
inheritance check
148
model
136
object parameters
136
option
130, 131, 136
package (CDM) check
136
relationship
144
replication (CDM) check
149
set error severity
130
warning
130
check parameter
column
123, 126
data type
37, 65

180

define
domain (CDM)
properties
standard
type
validation rule
client
business rule (CDM)
expression
close CDM
code
data item
option
package (CDM)
relationship
unique
code naming convention
column
check parameter
generate
rename
validation rule
variable
composite view
configure
OOM options
PDM options
convert
CDM to OOM objects
CDM to PDM objects
data type
correct
automatic
CDM
check
error
manual

123
50, 123, 126
123
123
123
22, 123, 126
26
26, 126
17
35
79
19
79
35, 79
171
123, 126
157
157
126
126
18
173
165
171
157, 160
160, 171
130
134, 135
134, 135
130
135

D
data item
add as entity attribute
associate domain
association
check model
code
copy
create from Browser

3
34, 60
36
105
139
35
54
31

Index

create from list
data type
define
delete
domain (CDM)
duplicate
error
non-divergence
option
properties
reuse
sort list
unique
unique code
use as entity attribute
validity check
data type
binary
bitmap
boolean
byte
character
conceptual
conversion in DBMS
convert to OOM
convert to PDM
data item
date
decimal
default
define
domain (CDM)
entity attribute
float
image
integer
length
map to OOM
map to PDM
money
number
OLE
precision
select
select from list
select from property sheet
select from the list

31
37, 66
30
33, 67
36
34
36
50
34, 54
30
4, 35, 60, 67
39
4
35
60
136
42, 44
46, 163
46, 163
44, 161
44, 161
45
161
160
171
160
37, 66
46, 163
44, 161
4
160
42, 43, 48, 50
64
44, 161
46, 163
44, 161
42, 44
171
160
44, 161
44, 161
46, 163
42, 44
37, 64
42
42, 43
43

serial
44, 161
show full name
4
time
46, 163
undefined
37, 42, 43, 46, 48, 66, 163
Data Type Full Name option
10
date data type
46, 163
DBMS data type conversion
160
decimal data type
44, 161
Default Data Type option
11
delete data item
67
dependent association (CDM)
103
detach CDM from workspace
17
display preference
association (CDM)
108
association link
109
entity
56
inheritance
122
package (CDM)
20
relationship
93
diverge from domain
10
domain (CDM)
3
business rule
50
CDM
40
check model
137
check parameter
50, 123, 126
create from Browser
41
create from list
41
data item
36
data type
42–44, 48, 50
define
40
diverge from
10
enforce
50
enforce coherence
4, 10
entity attribute
50, 63
length
42, 44
modify properties
48
non-divergence
50
precision
42, 44
properties
40
use
50
validation rule
126
validity check
136
variable
126
Domain and Attribute option
10
dominant relationship
87
duplicate data item
34

181

Index

E
E/R + Merise
enforce domain (CDM)
entity
add to inheritance
association
associative
change from association
change from relationship
check model
copy
create from Browser
create from diagram
create from list
define
delete
display preferences
entity attribute
generate table
identifier
inheritance
modify from list
modify from property sheet
properties
validity check
wizard
entity attribute
add
add to identifier
associate domain
association
attach to domain
check model
copy
create
create from data item
create from list
data item
data type
define
delete
domain (CDM)
entity
identifier
inheritance
list
mandatory

182

6
50
3
113
104
89
104
89
141
54
52
52
52
52
67
56
54, 67
160
54, 67, 69
110, 160
54
54
52, 54
136
89
34, 60
71
63
104
63
143
54
62
60
60
34, 60
64
59
67
50, 63
67
54, 67, 69
118
62, 67
66

optional
properties
relationship
reuse
specifying entity attribute
validity check
entity identifier check
entity/relationship
notation
ERD
CDM
Entity Relationship Diagram
Relationship tool
error
check model
severity
error message
CDM
data item
display
relationship
unique code
expression
business rule (CDM)
client
server
extended dependency (CDM)
extended link
check
code uniqueness
name uniqueness
extended model definition (CDM)
extended object
check
code uniqueness
name uniqueness

66
59, 118
89
60, 67
118, 120
136
143
6
4
2
2
3
130
130
130, 131, 134
36
134
79
36, 79
26, 126
26, 126
26, 126
12
149
150
150
11
149
149
149

F
file object
check
external
name uniqueness
float data type
foreign key
generate
generate from identifier
index

148
149
148
44, 161
167
169
157
169

Index

name
name template for generation

169
167

G
general option
generate
CDM
CDM from CDM
column
configure OOM options
configure PDM options
foreign key
foreign key name
index parameter
inheritance
new CDM
new model
new OOM
new PDM
OOM
OOM from CDM
OOM object
OOM object conversion
PDM
PDM from CDM
PDM object
PDM object conversion
PDM option
primary key
reference parameter
table
table parameter
update existing CDM
update model
validation rule
global model
CDM
check

35, 79
154, 155
155
157
173
165
157, 169
167
169
160
155
154
172
164
172–174
171
171
171
164, 165
157
157
160
165
157, 169
167
160
167
155
154
126
131
131

I
IDEF1X
identifier
child
copy
define
delete
designate

entity attribute
generate key
modify from list
modify from property sheet
parent
primary identifier
image data type
Include Sub-Objects tool
index
foreign key
generate
primary key
inheritance
add child entity
check model
child
complete
create
define
display preferences
entity attribute
generate
generation mode
link
mutually exclusive
parent
primary key
properties
specifying entity attribute
validity check
integer data type

54, 67, 71
157
73
73
117
72
46, 163
131
169
169
169
3
113
148
116
110
112
110, 117, 120
122
118
116
116, 117
112
115
116
117
110, 116
120
136
44, 161

L
list
arrange
order
location for file object
logical model

67
67
149
2

M
6
69
117
54
69
67
69

manual correction
map
CDM to OOM
CDM to PDM
Merise
association (CDM)
notation

135
171
160
6
95
4

183

Index

model
object selection
OOM options
open
option
PDM options
sub-object
model option
all objects
data item
data type full name
default data type
domain and attribute
notation
relationship
money data type

131
173
151
35, 79
165
131
5
9
10
11
10
6
10
44, 161

N
name
file object
foreign key
package (CDM)
primary key
name uniqueness
extended link
extended object
Name/Code Case Sensitive option
namespace for package (CDM)
non-divergence
data item
domain (CDM)
notation
Entity/Relationship
Merise
Notation option
number data type

184

171
174
171
174
172
171
171
35, 79
130, 131, 136
79
173
165
34, 54
35, 79
35, 79
79

P
148
169
19
169
150
149
4
19
50
50
4
4
6
44, 161

O
object
business rule (CDM)
CDM
object selection
check
model
package
OLE data type
OOM

code naming convention
enable transformations
generate object
generation option
generation parameter
map CDM object
object
option
CDM
check
code
configure for generated OOM
configure for generated PDM
data item
general
model
relationship

27
3
131
131
131
46, 163

package (CDM)
CDM
check model
code
comment
composite view
create
define
display preferences
name
namespace
object selection
properties
shortcut code uniqueness
shortcut generated as child table
validity check
PAM opened into CDM
PDM
enable transformations
generate
generate object
generation option
generation parameter
map CDM object
object
update
precision
primary identifier

18
136
19
19
18
19
18
20
19
19
131
19
137
137
136
151
165
164
157
165
164
160
157
164
42, 44
72

Index

primary key
child
generate
generate from identifier
index
inheritance
name

rule
117
169
157
169
117
169

R
reference
foreign key name
generate
reflexive association (CDM)
relationship
associative entity
bend
cardinality
change to entity
check model
code
create
create from Browser
create from diagram
create from list
define
dependent
display
display preferences
dominant
drag
entity attribute
ERD
error
example
mandatory
modify
modify from list
modify from property sheet
option
optional
properties
reflexive
sort list
termination point
unique code
Relationship option
replication (CDM) check

167
167
100
3
89
94
80, 91
89
144
79
78
76
76
76
75, 85, 87, 89
85
94
93
87
94
89
3
79
91
83
94
79
79
79
83
75, 79
78
90
81, 83
4, 79
10
149

S
save CDM
serial data type
server
business rule (CDM)
expression
shortcut code uniqueness in package
shortcut generated as child table
specifying attribute
create
list
specifying entity attribute
standard data type list
sub-object check
Sybase SQL Anywhere data types

17
44, 161
26
26, 126
137
137
120, 121
120, 121
118, 120
44
131
161

T
table generation
time data type
type of business rule (CDM)
typographic conventions

160, 167
46, 163
23
vi

U
undefined data type

37, 42, 43, 48, 66

V
validation rule
apply
business rule (CDM)
check parameter
column
domain (CDM)
generate
variable
column
domain (CDM)

123
126
126
126
126
126
126
126
126

W
warning in CDM check
warning message of last check

130, 131, 134, 135
134

185

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