title: MySQL with IFNULL in where clause
body: <p>I have MySQL table with this row :</p>
  
  <pre><code>+----------+--------+------+-------+
  | list_uid | sku    | qty  | verif |
  +----------+--------+------+-------+
  |       49 | 024522 | 10   | 8     |
  +----------+--------+------+-------+
  </code></pre>
  
  <p>I try to select this row with this query :</p>
  
  <pre><code>SELECT
    *
  FROM
    ae_rf_list_picked
  WHERE
    `qty` != 0 AND
    IFNULL(`verif`, 0) &lt; `qty` AND 
    `sku` = '024522' AND 
    `list_uid` = 49
  </code></pre>
  
  <p>I don't understand why this row is not return by this query.
  If I remove this part  </p>
  
  <blockquote>
    <p>IFNULL(<code>verif</code>, 0) &lt; <code>qty</code> AND</p>
  </blockquote>
  
  <p>the query return the row.</p>