AJAX issues (Cannot get ajax to successfully work)

I asked a question earlier today with little luck: AJAX within a foreach loop

i was put on the right path but the answer provided has got me more confused than ever. Whenever i click on my anchor tag with the ajax call, nothing happens. When i go into console view and check the network tab, it says the call was a success. when i go further into the call details it shows all the data i sent and the page it went too. The code on page_id=252 does not fire whatsoever.

I am using wordpress for this assignment. I am using custom templates to hold my PHP code. not a plugin.

I have two pages:

Index.php
ajaxcall.php

Index.php (?page_id=## is default permalinks to my wp pages. this location is valid.)

    <script type="text/javascript">
    function onClickingThis(rem_opt,vidid){
      $.ajax({
          url: '?page_id=252', 
          type: 'POST',
          data: {action: 'update_this_func', remove_option: rem_opt, uservideo_id: vidid },
          dataType: 'json',
          success: function(response){
            console.log('works');
          }
      });
    }
</script>

// all my php code, for everything on the page.
<a href="#"  onclick="onClickingThis(0,1)></a>

ajaxcall.php

function update_this_func(){
$remove_option = $_POST['remove_option'];
$uservideo_id  = $_POST['uservideo_id'];

global $wpdb;

$wpdb->query("UPDATE " . $wpdb->prefix."uservideo
              SET is_removed =" . $remove_option . "
              WHERE uservideo_id =" . $uservideo_id );

return json_encode(['status' => 'Updated!']); // return status as json
}

This code was provided by user: Ervald, but he did not want to elaborate on his code. My success message is not working for the ajax, but i am not getting any errors in the console. How do i debug my ajax? is my ajax not set up properly? If this is not the right way to use ajax please let me know. Any help is GREATLY appreciated.

there have been 2 problems in your PHP script:
1. the function was not called
2. the return-value of the function was not echoed.

(in order to respond to an AJAX call, the called url always needs to output something - JSON in the most cases. AJAX can't access PHPand thus can't read PHP return values.)

here is the fixed version:

function update_this_func($remove_option, $uservideo_id){

    global $wpdb;

    $wpdb->query("UPDATE " . $wpdb->prefix."uservideo
                  SET is_removed =" . $remove_option . "
                  WHERE uservideo_id =" . $uservideo_id );

    return json_encode(['status' => 'Updated!']); // return status as json
}
echo update_this_func($_POST['remove_option'], $_POST['uservideo_id']);