Sybase Powerdesigner 7.5, User Manual

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Defining domains
120
Defining domains
Domains help you identify the types of information in your project. They
define the set of values for which an attribute is valid. Applying domains to
attributes makes it easier to standardize data characteristics for attributes in
different classes.
In an OOM, you can associate the following information with a domain:
♦
Data type, length, and precision
♦
Check parameters
♦
Business rules
Domain properties
Each domain definition includes the following properties:
Property Description
Maximum
length
Name Name for the domain 254
Code Reference name for the domain 254
Comment Descriptive label for the domain —
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 —
A domain definition can also include the following properties, which have
associated values or information used by attributes attached to the class:
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