The value of the validation expression in the database schema for the database field that corresponds to the buffer-field.
The VALIDATE-EXPRESSION attribute lets you write user input validation code for interfaces that the AVM's automatic user input validation does not support.
Data type: CHARACTER
Access: Readable/Writeable
Applies to: Buffer-field object handle
If a buffer-field is associated with a dynamic browse column, you should set the buffer-field's VALIDATE-EXPRESSION attribute before the dynamic browse column is added to the browser (via ADD-LIKE-COLUMN( )). The validation expression is compiled at this time. If the VALIDATE-EXPRESSION attribute is changed later, it is ignored.