The Validation option in the Modify Table dialog box allows you to specify validation criteria and a message for record deletions.
Note: You should use table validation for backward compatibility for procedure-driven applications. For event-driven programs, use table delete triggers instead of table validation.
If you choose Validation, the Table Validation dialog box shown in the following figure appears.
Figure 22. Table Validation dialog box
The Table Validation dialog box contains the following fields:
Valmsg —Specifies the message that appears when a user tries an invalid deletion. There is no limit to the number of characters you can enter, but a message up to 63 characters long can fit onto the two message lines without scrolling.
Valexp — Specifies the criteria for valid deletions. For example, to restrict deleting customers in the Customer table to those customers who have no outstanding orders, enter the following:
Valmsg —Specifies the message that appears when a user tries an invalid deletion. There is no limit to the number of characters you can enter, but a message up to 63 characters long can fit onto the two message lines without scrolling.