title: SSIS Using Derived column to reference column from same table
body: <p>I am trying to import an xls spreadsheet into a table, and one of the columns needs to be derived from a different column in the same table. I would like to do this during the import phase rather then creating a SQL Task to do it after the import. I am horrible when it comes to creating expressions in SSIS, so this is probably an easy task - but I just can't get it right. </p>
  
  <pre><code>DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,columndata)+1,0))
  </code></pre>
  
  <p>That is the expression that I am trying to use. </p>