title: #1111 - Invalid use of group function
body: <p>I'm getting an error when trying to run this query:</p>
  
  <pre><code>UPDATE tbl1, tbl2 SET `tb1`.field=SUM(tbl2.grade) WHERE tbl2.word=tbl1.word
  </code></pre>
  
  <p>This is the error: <code>#1111 - Invalid use of group function</code></p>
  
  <p>I basically trying to get the sum of a field from tbl2 and insert it into tbl1 </p>