Is it possible to insert a row but only if a value does not already exist?

Question

Is it possible to insert a row, but only if one of the values already in the table does not exist?

I\'m creating a Tell A Friend with referral points for an eco

Answer 1

Most likely something like:

IF NOT EXISTS(SELECT * FROM myTable WHERE Email=@Email) THEN INSERT INTO blah blah

That can be rolled into one database query.