How to insert a record only if it doesn't exist in MySQL?

NickF

I need to check a record for duplicates before inserting. What is the best way to do this for a database having a large number of records without affecting the performance?

DavidM

INSERT IGNORE INTO table will do the trick.

see http://bogdan.org.ua/2007/10/18/mysql-insert-if-not-exists-syntax.html