title: Referencing one computed column from another
body: <p>I'm using SAS Enterprise Guide 7.1 and i'm having a problem with something that seems fairly basic. I'll simplify the problem but fundamentally I have one computed column (Computed_column1) that uses a CASE/WHEN statement e.g.</p>
  
  <pre><code>CASE
  WHEN x &gt; y THEN "TRUE"
  ELSE "FALSE"
  END
  </code></pre>
  
  <p>I'd like to reference the first computed column in a second computed column (Computed_column2) but instead of referring to the computed column name the advanced expression tab in the query builder pulls through all of the contents from the first computed column. Therefore if i need to change the first column i'll have to change the second one also.</p>
  
  <p>So my second computed column looks something like this:</p>
  
  <pre><code>CASE
  WHEN (CASE WHEN x &gt; y THEN "TRUE" ELSE "FALSE" END) &gt; z THEN "TRUE"
  ELSE "FALSE"
  END
  </code></pre>
  
  <p>When i'd like it to be some type of dynamic reference like:</p>
  
  <pre><code>CASE
  WHEN Computed_column1 &gt; z THEN "TRUE"
  ELSE "FALSE"
  END
  </code></pre>
  
  <p>This way if the first computed column changes the second will also. Is this not possible?</p>
  
  <p>Cheers in advance.</p>