Defining a validation rule in the DataWindow painter

Validation rules you assign to a column in the Database painter are used by default when you place the column in a DataWindow object. You can override the validation rule in the DataWindow painter by defining an ad hoc rule for one specific column.

To specify a validation rule for a column in the DataWindow painter:

In the DataWindow painter, select View>Column Specifications from the menu bar.

The Column Specification view displays.

The sample displays the Column Specification view with three sample column names listed. The third row displays the column Name Salary of Type decimal ( 3 ). For Salary, the initial value displayed is 3000, the Validation Expression is real ( get text ( ) )greater than 0, and the Validation Message is " Sorry ! The value must be greater than zero. "

Create or modify the validation expression. To display the Modify Expression dialog box, display the pop-up menu for the box in which you want to enter a Validation Expression and select Expression. Follow the directions in “Specifying the expression”.
(Optional) Enter a string or string expression to customize the validation error message.

For more information, see “Customizing the error message”.
(Optional) Enter an initial value.

Used for current column only If you create a validation rule here, it is used only for the current column and is not saved in the extended attribute system tables.