Cara menemukan pasangan simetris di SQL
SELECT f1.X, f1.Y FROM Functions AS f1 WHERE f1.X = f1.Y GROUP BY f1.X, f1.Y HAVING COUNT(*) > 1
Attractive Anaconda
SELECT f1.X, f1.Y FROM Functions AS f1 WHERE f1.X = f1.Y GROUP BY f1.X, f1.Y HAVING COUNT(*) > 1