title: join with a static value for a column in zf2
body: <p>I'm writing a PHP application using zend framework 2.2.2.
  I'm trying to create a select query with a join that contains a static value condition.</p>
  
  <p>this is my code:</p>
  
  <pre><code>    $this-&gt;select-&gt;join('global_image_link','global_image_link.table_pkey=drink_flavor.drink_flavor_id AND global_image_link.global_image_type_id=2',array())
  </code></pre>
  
  <p>now the end of the query contains the following:</p>
  
  <pre><code>global_image_link.global_image_type_id=2
  </code></pre>
  
  <p>when i do getSqlStringForSqlObject to return the query the end of the query is</p>
  
  <pre><code> AND `global_image_link`.`global_image_type_id`=`2`
  </code></pre>
  
  <p>because it adds `` to the number it searches for column called 2 instead of the number 2. </p>
  
  <p>I guess i need to escape that number somehow or wrap it with some class. </p>
  
  <p>any ideas how to resolve the issue?</p>
  
  <p>thanks</p>