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WITH yourTable AS ( SELECT 'User1' AS First_User, NULL AS Second_User, 427 AS Count UNION ALL SELECT 'User3', NULL, 69 UNION ALL SELECT 'User2', NULL, 499 UNION ALL SELECT 'User1', 'User1', 1 UNION ALL SELECT 'User4', 'User2', 48 UNION ALL SELECT 'User5', 'User2', 13 ) SELECT User, SUM(Count) AS Count FROM ( SELECT First_User AS User, SUM(Count) AS Count FROM yourTable WHERE First_User IS NOT NULL GROUP BY First_User UNION ALL SELECT Second_User, SUM(Count) FROM yourTable WHERE Second_User IS NOT NULL GROUP BY Second_User ) t GROUP BY User ORDER BY User;
User
Count
User1
429
User2
560
User3
69
User4
48
User5
13