title: ssis assign a value to a guid when null
body: <p>I have the following expression in ssis</p>
  
  <pre><code>(ISNULL [rowguid]? (DT_WSTR, 255)"00000000-0000-0000-0000-000000000000":[rowguid])
  </code></pre>
  
  <p>What I want is to assign that guid if there is null present. I just can't seem to get it working</p>