title: Incorrect parameter when using IsNull in MySQL
body: <p>I've been trying to use the <code>IsNull()</code> function to ensure that there is a value for a field.</p>
  
  <pre><code>SELECT crawled.id,
         IsNull(sranking.score,0) as Score,
         crawled.url,
         crawled.title,
         crawled.blurb
  FROM crawled
      LEFT JOIN sranking ON crawled.id = sranking.sid
  WHERE crawled.body LIKE '%".$term."%'
  ORDER BY Score DESC LIMIT " . $start . "," . $c
  </code></pre>
  
  <p>But I get the error message:</p>
  
  <blockquote>
    <p>Incorrect parameter count in the call to native function 'IsNull'</p>
  </blockquote>
  
  <p>Anybody have any ideas? I'm pretty new to MySQL. </p>