public static function get_all_form_attachments($form_id)
 {
     global $wpdb;
     $field_ids = self::get('FIELDS', array('field_type' => 'File', 'form_id' => $form_id), array('%s', '%d'), 'col', 0, 99999, 'field_id', null, false);
     $table_name = RM_Table_Tech::get_table_name_for('SUBMISSION_FIELDS');
     $unique_id_name = RM_Table_Tech::get_unique_id_name('SUBMISSION_FIELDS');
     if ($unique_id_name === false) {
         return null;
     }
     if ($field_ids) {
         $qry = "SELECT `value` FROM {$table_name} WHERE ";
         $i = 0;
         foreach ($field_ids as $field_id) {
             if ($i === 0) {
                 $qry .= "`field_id` = {$field_id} ";
             } else {
                 $qry .= "OR `field_id` = {$field_id} ";
             }
             $i++;
         }
         $qry .= "ORDER BY `{$unique_id_name}`";
         $results = $wpdb->get_col($qry);
     } else {
         return false;
     }
     if (empty($results)) {
         return false;
     }
     return $results;
 }