How to check if MySQL returns null/empty?

Question

In DB I have a table with a field called fk_ownerID. By default, when I add a new table row, the fk_ownerID is empty. In Toad for MySQL, this is sh

Answer 1

if ( (strlen($ownerID) == 0) || ($ownerID == '0') || (empty($ownerID )) )

if $ownerID is NULL it will be triggered by the empty() test

https://www.php.net/empty