wordpress ajax return 0

So, if you want it to fire on the front-end for both visitors users and logged-in users, you can do this:

add_action( 'wp_ajax_my_action', 'my_action_callback' );
add_action( 'wp_ajax_nopriv_my_action', 'my_action_callback' );

Example

add_action( 'wp_ajax_GetPostMedia', 'GetPostMedia' );
add_action( 'wp_ajax_nopriv_GetPostMedia', 'GetPostMedia' );

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