title: sql Cast when datetime column null or empty
body: <p>like to cast regdate col as datetime when regdate column not null or empty and regdate older than 2 years.if it is empty I like to insert regdate as 1900-01-01.</p>
  
  <pre><code>id  name    regdate
  555 bob     24/06/2013 00:00:00
  556 tom     24/07/2013 00:00:00
  557 jack    24/10/2008 00:00:00
  558 susan   24/11/2009 00:00:00
  559 emily   
  560 Mert    
  
  
  SELECT *, CAST(idate AS DATETIME) AS finalDate
      INTO #tempFinal
      FROM #tempA
      WHERE CAST(idate AS DATETIME) &lt; DATEADD(YEAR, -2, GETDATE())
      OR idate IS NULL OR idate = ''
  </code></pre>