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  1. Prepare
  2. SQL
  3. Advanced Join
  4. Symmetric Pairs
  5. Discussions

Symmetric Pairs

  • cgaton0
     + 0 comments

    MySQL

    SELECT DISTINCT f.x, f.y
FROM (SELECT x, y, 
      ROW_NUMBER() OVER (ORDER BY x ASC) AS id
      FROM Functions) AS f
INNER JOIN (SELECT x, y, 
            ROW_NUMBER() OVER (ORDER BY x ASC) AS id
            FROM Functions) AS f2 ON f.x = f2.y
WHERE f.x <= f.y AND f2.x = f.y AND f.id != f2.id
ORDER BY f.x