title: How to paginate two tables in zend framework
body: <p><strong>Books has the following fields</strong>  </p>
  
  <ul>
  <li>book_id </li>
  <li>book_name</li>
  <li>book_auther</li>
  <li>book_pub_date</li>
  </ul>
  
  <p><strong>category table has</strong></p>
  
  <ul>
  <li>category_id</li>
  <li>category_name</li>
  </ul>
  
  <p><strong>placement table has</strong></p>
  
  <ul>
  <li>placement_id</li>
  <li>placement_category_id(FK)</li>
  <li>placement_book_id(FK)</li>
  </ul>
  
  <blockquote>
    <p>Now we want to use pagination in index controller to
    select books with specific category ?<br>
    <em>all tables are in one database</em>  </p>
  </blockquote>
  
  <hr>
  
  <p>Note: I have separated model for each table and all tables are related each other with $_referenceMap<br>
  I use $adapter = new Zend_Paginator_Adapter_DbTableSelect($select);<br>
  the question is : how to make $select ?</p>