Validation Rules

The following is part of the Microsoft help screen on validation rules, for more details refer to the on-line Access help documentation.

 

The following table contains expression examples for the ValidationRule and ValidationText properties.

 

Validation Rules
ValidationRule property ValidationText property
<> 0 Entry must be a nonzero value.
> 1000 Or Is Null Entry must be blank or greater than 1000.
Like "A????" Entry must be 5 characters and begin with the letter "A".
>= #1/1/96# And <#1/1/97# Entry must be a date in 1996
DLookup("CustomerID", "Customers", "CustomerID = Forms!Customers!CustomerID") Is Null Entry must be a unique CustomerID (domain aggregate functions are allowed only for form-level validation).