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

This works if you have a unique index or primary key on the column (EmailAddr in this example):

INSERT IGNORE INTO Table (EmailAddr) VALUES ('test@test.com')

Using this if a record with that email already exists (duplicate key violation) instead of an error, the statement just fails and nothing is inserted.

See the MySql docs for more information.