title: Move duplicate values to another column
body: <p>I have a table with pairs of entries based on the column id_location.</p>
  
  <pre><code>"id_image",  "score",  "stddev", "id_image2", "score2", "stddev2", "id_location"
  3484,        0.90422,  0.06476,  NULL,        NULL,     NULL,      13
  18,          0.71598,  0.06101,  NULL,        NULL,     NULL,      13
  </code></pre>
  
  <p>If I wanted to merge duplicates for id_location and move them to a different column so each row is unique, how would I do that?  </p>
  
  <p>I looked at transpose and pivot but those seem slightly different.</p>
  
  <p>This would be the resulting table:</p>
  
  <pre><code>"id_image",  "score",  "stddev", "id_image2", "score2", "stddev2", "id_location"
  3484,        0.90422,  0.06476,  18,          0.71598,   0.06101,  13
  </code></pre>