Home Forums Backend Issues (wp-admin) Check if value already exist Reply To: Check if value already exist

  • This could be done, but not directly, it will take a little work. What you’d need to do is set up an acf/validate_value filter outlined here

    In the filter you can then do a query of all of the posts to see if there is another post with the same field value and return an error. Something along the lines of:

                'validate_field_name_filter, 10, 4)
    function validate_field_name_filter($valid, $value, $field, $input) {
      if (!$valid || $value == '') {
        return $valid;
      // query posts for the same value
      // for more info see
      global $post; 
      $args = array(
        'post_type' => 'post',  // or your post
        'post__not_in' => array($post->ID), // do not check this post
        'meta_query' => array(
            'key' => 'field_name',
            'value' => $value
      $query = new WP_Query($args);
      if (count($query->posts)) {
        // found at least one post that
        // already has $value
        $valid = 'There is already a post using this video';
      return $valid;