Performing an UPDATE or INSERT depending whether a row exists or not in MySQL

Question

In MySQL, I\'m trying to find an efficient way to perform an UPDATE if a row already exists in a table, or an INSERT if the row doesn\'t exist.

I\'ve found two possi

Answer 1

If you're doing a lot of these, it might be worth writing them to a file, and then using 'LOAD DATA INFILE ... REPLACE ...'