Conditional success callback based on Ajax Response not working

Save yourself some effort and examine the wp_send_json_success() and wp_send_json_error() functions instead. These will let you send data back from PHP and automatically send back success values for the javascript code to examine.

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