Best way to check if MySQL results returned in PHP?

Question

I\'m looking for the best way to check and see if any results were returned in a query. I feel like I write this part of code a lot and sometimes I get errors, and sometimes

Answer 1

Of all the options above I would use

if (mysql_num_rows($result)==0) { PERFORM ACTION }

checking against the result like below

if (!$result) { PERFORM ACTION }

This will be true if a mysql_error occurs so effectively if an error occurred you could then enter a duplicate user-name...