WordPress Ajax not function as I expect… what’s wrong?

First try to perform this without JS altogether. Just visit link yoursite.com/wp-admin/admin-ajax.php?action=testthisajax.

0 seems like something kinda works, but not quite. If I remember right failed requests should be -1.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)