My AJAX API plugin isn’t working

There is no PHP function alert, that’s why your function throws an error and doesn’t proceed with the rest of your code. You have to return something from the LogHit_callback function using return (or echo it with echo) and then alert it with JavaScript, that is add following code to your post function:

jQuery.post( 'http://www.test.com/wp-admin/admin-ajax.php', data, function( r ) {
    alert( r );
});

I believe that this is the correct syntax for post(). Remember that you can always debug AJAX requests with browser’s developer tools. You will then know exactly what’s going on.

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