Record Validation Rule

[Laura]

I have a table with 5 Y/N fields. I want to make it required that only one
can be checked. I know how to do this at a form level. However, I think
that people who build update queries and change data in the table forget to
clear out the old field. I want to force this at table level. Is this
possible?

 

[John Vinson]

I have a table with 5 Y/N fields. I want to make it required that only one
can be checked. I know how to do this at a form level. However, I think
that people who build update queries and change data in the table forget to
clear out the old field. I want to force this at table level. Is this
possible?

Well, it violates normal form: fields should NOT be mutually
dependent.

Might you consider instead using a single Integer field with values 1
to 5? The user interface on a Form could be an Option Box with five
checkboxes; only one will be able to be checked.

John W. Vinson[MVP]