Sybase Powerdesigner 7.5, User Manual

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Defining identifiers
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Defining identifiers
An identifier is a class attribute, or a combination of class attributes, whose
values uniquely identify each occurrence of the class. An identifier is the
OOM equivalent of a CDM identifier or a primary key or an alternate key in
a PDM.
Each class must have at least one identifier. If a class has only one identifier,
than it is designated by default as the primary identifier for the class. A
primary identifier is the main identifier for a class.
You can attach attributes or business rules to an identifier.
Identifier properties
An identifier has the following properties:
Property Description
Maximum
length
Name Name of the identifier 254
Code Reference name for the identifier 254
Comment Descriptive comment for the identifier —
Class Name of the class to which the identifier belongs to 254
Primary
identifier Indicates that the identifier is the primary identifier of
the class. There can only be one primary identifier for
a given class —
An identifier definition also includes the following properties, which are
defined on associated property sheets:
Property Description
Attribute Defines the characteristics of an identifier
Business rules A rule that your business follows. Business rules guide and
document the creation of a model