I would like designate a field be unique only when it has data in it. Our patient master contains a field called medical record id. This field needs to be unique only when an id is entered into it. Blanks in this field are ok, but if someone does enter a value into the field, I want to ensure that it is a unique value. I thought I could do this by just checking the "unique value" box on the validation tab of the field options. I have not checked the "not empty" box, so I thought that FM would allow this field to be empty. Here is a print screen of how the field is set up:
I appreciate any help on this.