Avoiding Duplicates

[LindaH]

I am building a database with family information including social security
numbers for family members. I want to avoid including someone in more than
one family by not allowing a duplicate ssn. I'm not sure how to go about
doing this since there are several fields with ssn's for each family member.

Any suggestions?

 

[John W. Vinson]

I am building a database with family information including social security
numbers for family members. I want to avoid including someone in more than
one family by not allowing a duplicate ssn. I'm not sure how to go about
doing this since there are several fields with ssn's for each family member.

Any suggestions?

Normalize your incorrect database structure.

The SSN (if it should be in your table AT ALL, it may violate some privacy
laws) should exist only once, in one People table. Each person, regardless of
how that person is related to other people, should have their own record.

Perhaps you could post a description of your table structure; it's quite
possible that someone could suggest a better table design.