Question

I have a mySQL table with duplicate entries (perhaps in some cases multiple duplicates). I have column called id, which may contain duplicate ids and one called unique id which, as the name suggest contains unique ids. Using the following SQL statement I am able to select the duplicate row

SELECT id,
COUNT(id) AS NumOccurrences
FROM `TABLE 3`
GROUP BY id
HAVING ( COUNT(id) > 1 )

but how do I delete (all but one of) them?

Answer 1

DELETE t1 FROM test t1, test t2 WHERE t1.unique_id > t2.unique_id AND t1.id = t2.id;