title: Why do I get a different SQL-behaviour on two different machines?
body: <p>Why does this query</p>
  
  <pre><code>;WITH CTE AS 
  (
      SELECT 
           T_Installation.IS_UID 
          ,T_Installation.IS_No_Intern
          ,T_Installation.IS_No_Intern
      FROM T_Installation 
      WHERE IS_IS_UID IS NULL 
  
      UNION ALL 
  
      SELECT 
              T_Installation.IS_UID
          ,T_Installation.IS_No_Intern
          ,T_Installation.IS_No_Intern 
      FROM CTE 
  
      INNER JOIN T_Installation 
          ON T_Installation.IS_IS_UID = CTE.IS_UID 
  )
  SELECT * FROM CTE 
  -- ORDER BY IS_No_Intern 
  </code></pre>
  
  <p>run without exception (on my machine), </p>
  
  <p>while this query</p>
  
  <pre><code>;WITH CTE AS (
      SELECT 
           T_Installation.IS_UID 
          ,T_Installation.IS_No_Intern
          ,T_Installation.IS_No_Intern
      FROM T_Installation 
      WHERE IS_IS_UID IS NULL 
  )
  SELECT * FROM CTE 
  </code></pre>
  
  <p>throws</p>
  
  <blockquote>
    <p>Error 8156 <br />
    The column IS_No_Intern was specified multiple times for
    [whatever].</p>
  </blockquote>
  
  <p><br />
  (on my machine)</p>
  
  <p>On ano<strong>ther sql-server, same server-version</strong>, <strong><em>both</em></strong> variants throw an error...</p>