How many-to-many mass attach problem

Hi,

is it possible with eloquent in a many-to-many relationship to mass attach a bunch of ids and ignore those already attached ?

do {
            $data_ids = array();
            foreach($jsonArray as $json) {
              $page = \App\Page::createOrUpdatePage($json);
              array_push($data_ids, $page->id);
            }
            $this->user->pages()->attach($data_ids);
          }
          while ($edge = $this->fb->next($edge));

In this case, if $this->user->pages() already contains some ids of $data_ids, i get an SQL error :

"SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1-1' for key 'PRIMARY' (SQL: insert into `page_user`