title: Select AS not working in interbase
body: <p>works</p>
  
  <pre><code>select payeeid, EXTRACT(WEEKDAY FROM checkdate) as DOW, 
  (bankcleared - checkdate) as DateDiff  
  from Master  
  where (bankcleared is not null)  
  order by payeeid, DOW, DateDiff  
  </code></pre>
  
  <p>adding <code>DateDiff</code> to <code>Where</code> - does not work  </p>
  
  <pre><code>select payeeid, EXTRACT(WEEKDAY FROM checkdate) as DOW, 
  (bankcleared - checkdate) as DateDiff  
  from Master  
  where (bankcleared is not null)  AND (DateDiff &gt;= 1)  
  order by payeeid, DOW, DateDiff  
  </code></pre>