title: how to use IN-function within Zend_Select
body: <p>I different string values komma separated out of a form.</p>
  <p>In the code I cast them and then it looks like this:</p>
  <p>$kritkeyword ='test, abc, xyz';</p>
  <p>Now I want to use the variable within an IN-function. In original sql ist would be:</p>
  <pre><code>where keyword IN ('test', 'abc', 'xyz')
  </code></pre>
  <p>In my code I tried to do the following:</p>
  <pre><code>$select-&gt;where('keyword IN (?)', $kritkeyword);
  </code></pre>
  <p>I also tried:</p>
  <pre><code>$select-&gt;where(['keyword IN ?' =&gt;$kritkeyword]);
  </code></pre>
  <p>Until now I had different ideas how to write it, but I always get a sql error. So how to do this correct?</p>