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# If you want to keep the row with the lowest id value: | |
DELETE n1 FROM names n1, names n2 WHERE n1.id > n2.id AND n1.name = n2.name | |
# If you want to keep the row with the highest id value: | |
DELETE n1 FROM names n1, names n2 WHERE n1.id < n2.id AND n1.name = n2.name |
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--Find Duplicates | |
SELECT t.ID, t.id_A, t.id_B | |
FROM ( | |
SELECT id_A, id_B | |
FROM table_name | |
GROUP BY id_A, id_B | |
HAVING count(*) > 1 | |
) x, table_name t | |
WHERE x.id_A = t.id_A AND x.id_B = t.id_B | |
ORDER BY t.id_A, t.id_B | |
--Delete duplicates | |
DELETE FROM table_name WHERE id IN ( | |
SELECT * FROM ( | |
SELECT t.ID | |
FROM ( | |
SELECT id_A, id_B | |
FROM table_name | |
GROUP BY id_A, id_B | |
HAVING count(*) > 1) x, table_name t | |
WHERE x.id_A = t.id_A AND x.id_B = t.id_B | |
ORDER BY t.id_A, t.id_B | |
) AS p | |
) |
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