title: Duplicate rows, different PK
body: <p>I have this query :</p>
  
  <pre><code>SELECT pih.PID, piv.TSV, piv.Variable_ID, piv.Value_ID, piv.Manual_Value
  FROM Process_Instance_Value AS piv
  INNER JOIN Process_Instance_History AS pih ON piv.PID = pih.PID
  WHERE piv.Variable_ID IN ( SELECT Variable_ID 
                             FROM someTable 
                             WHERE Transition_ID = @someValue) 
  AND piv.PID = @someValue
  </code></pre>
  
  <p>I get this :</p>
  
  <p><img src="https://i.stack.imgur.com/xw6wM.jpg" alt="enter image description here">
  <br/>
  My problem is that those rows are duplicate for the use I want them at this point.
  Is it possible to only get rows on DISTINCT TSV? Or something like that?</p>
  
  <p>Thank you</p>