Chapter 2 Conceptual Data Model Basics

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. You can select any or all of the following attribute properties:

• Data type - Data type, length, and precision
• Check - Check parameters, such as minimum and maximum values
• Rules - Business rules
• Mandatory - Entity, association and inheritance attribute mandatory property

When you apply the Enforce non-divergence options You are asked if you want to apply domain properties to attributes currently attached to the domain. If you click OK, the attribute properties are modified in order to be consistent with the properties of the domain to which they belong.

When you modify the properties of a domain The properties of the attributes attached to the domain are updated provided these properties are selected in the Model Options dialog box.

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 is displayed as unavailable and can not be modified.

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 appropriate Enforce non-divergence model option.

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.

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