Question

I have User table in my DB.

A user has the fields name, company_id and status: boolean, 1- live, 0- deleted.

When a user is deleted, his status is set to 0.

The combination of a live user name in a company should be unique. After a user is deleted, I don’t mind that a user should be created with the same name for the company.

My question is how do I define a uniuqe constrain for the fields name, company_id and status=1 (It’s not a uniuqe constrain on those three field becuase I don’t mind that the combination of name-company_id-0 will appear a few times in the table).

Thanks,

Dvora

Answer 1

Use NULL value for deleted users.
Unique key allows unlimited number of NULL values.

Update: Don’t touch user name, NULL in status field is enough.