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Assign Default and Validation Constraints to a Column

You can use the Constraint tab in the Table Column Editor to assign the default and validation constraints for a table column.

To assign default and validation constraints to a column

  1. Right-click the column on the diagram for which you want to specify default and validation constraints and click Column Properties.

    The Table Column Editor opens.

  2. Click the Constraint tab and work with the following options.
    Check Constraints

    Specifies the validation rule to attach to the selected column. Select the validation rule that you want from the drop-down list. You can also use the drop-down list to open the Validation Rule Editor to view or modify an existing validation rule or create a new one. If the Use Inherited Constraint check box is selected this means that this property is inherited from the column's domain. If you do not want this property to be inherited, simply clear the check box and select a validation rule from the drop-down list.

    Default

    Specifies the default value to attach to the selected column. Select the default value that you want from the drop-down list. You can also use the drop-down list to open the Default Value Editor to view or modify an existing default value or create a new one. If the Use Inherited Default Value check box is selected this means that this property is inherited from the column's domain. If you do not want this property to be inherited, simply clear the check box and select a default value from the drop-down list.

    Is Enforced

    Specifies whether or not the constraint is enforced by the database manager

    during insert, update, or delete operations.

    Is Query Optimization Disabled

    Specifies whether or not you want to use the constraint or functional dependency for query optimization when appropriate.

  3. Click Close.

    The default and validation constraints are specified and the Table Column Editor closes.