ConstraintExpression Property (Constraint)

Specifies the expression used to test a constraint.

Syntax

Constraint.ConstraintExpression = variant

Remarks

Read/Write at run time and design time. Property applies to Constraint object.

This property specifies the constraint expression that is evaluated to test a constraint. If it evaluates to True, the constraint is satisfied, otherwise it is not.

See Validation and Constraints for more information on constraints.

See True DataControl Expressions for more information about expressions in general. Evaluation rules for ConstraintExpression are as follows:

Expression Level: Record level

Synchronous Evaluation: For field-level constraints, evaluated before the field is modified. For record-level constraints, evaluated before the modified record is posted to the database, or before the TData control is repositioned to a different record.

Asynchronous Evaluation: No action.