Get the first parent id of a simple product woocommerce

wc_get_first_parent.php

function wc_get_first_parent($prod_id) {
  $group_args = array(
   'post_type' => 'product',
   'meta_query' => array(
     array(
       'key' => '_children',
       'value' => 'i:' . $prod_id . ';',
       'compare' => 'LIKE',
     )
     ),
     'fields' => 'ids' // THIS LINE FILTERS THE SELECT SQL
  );
  $parents = get_posts( $group_args );
  return count($parents) > 0 ? array_shift($parents) : false;
}