This is a bad choice for a PK as SSN is not unique. There are a small number of duplicates that have been issued.

>I am trying to set a primary key for a character field and a date field through an expression. I have thhe following:
>
>ssnumber+orderdate
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>ssnumber is a character field and the orderdate is a date field. When I try and save it I get the following:
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>Operator/operand type mismatch
>
>Newbie and need help.