title: Codeigniter: Join with 'where in' clause
body: <p>I want to join tables to list books of two categories fiction and romance. How do I do a JOIN with a WHERE IN clause (is that even possible? sorry, noob here) </p>
  
  <p>Here's where I'm stuck at: </p>
  
  <pre><code>$categories = array(10,12);
  $query = select()-&gt;from('books');
  $query-&gt;join('genre_map','genre_map.gid IN ('.implode(",", $categories).')');
  </code></pre>
  
  <p>Jn Table genre_map: bookid, genre_id</p>
  
  <p>Any SQL Query/CodeIgniter help would be much appreciated.</p>