How to determine if a MySQL update query succeeded when the data passed in the query is the same as what is already in the database?

Question

Let\'s say you have a form with pre-populated data from your database, and you allow your users to make changes and save the form. If the user clicks the save button without mak

Answer 1

[affected_rows()][1] is -1 if a query fails, not zero.

[1]: http://www.php.net/manual/en/function.mysql-affected-rows.php

It may return 0 if no changes were made to the row (same values), or if mysql didnt find a row to update. It will only return -1 due syntax erro