title: How can i force laravel to do batch(multiple) insert in sync() method?
body: <p>When i use <code>sync()</code> method laravel do a lot of separate insert queries in  my intermediate table like this:</p>
  
  <pre><code>INSERT INTO `tag_user` (`user_id`, `tag_id`) VALUES ('59', '60')
  INSERT INTO `tag_user` (`user_id`, `tag_id`) VALUES ('59', '61')
  </code></pre>
  
  <p>I want it to do one multiple insert like this:</p>
  
  <pre><code>INSERT INTO `tag_user` (`user_id`, `tag_id`) VALUES ('59', '60'), ('59', '61')
  </code></pre>
  
  <p>Is it possible? I'm using MySql. It would be nice to have <code>attach()</code> method that will accept array as <code>detach()</code> method do. Did someone do this?</p>