Move Duplicate Values To Another Column

I have a table with pairs of entries based on the column id_location. 'id_image', 'score', 'stddev', 'id_image2', 'score2', 'stddev2', 'id_location' 3484, 0.90422, 0.0647

Solution 1:

This would do it, with the higher id_image appearing in the first slot:

INSERT INTO new_table
SELECT t1.id_image, t1.score, t1.stddev, t2.id_image,
  t2.score, t2.stddev, t1.id_location
FROM old_table t1
JOIN old_table t2
ON t2.id_location = t1.id_location
  AND t2.id_image < t1.id_image

Solution 2:

Maybe using subqueries :

UPDATE your_table
 SET
  score2 = (SELECT score FROM your_table WHERE id_image = 3484),
  stddev2 = (SELECT stddev FROM your_table WHERE id_image = 3484),
 WHERE id_image = 18;