MySQL удалить дубликаты рядов, но держите один
DELETE c1 FROM contacts c1
INNER JOIN contacts c2
WHERE
c1.id > c2.id AND
c1.email = c2.email;
Stefan Schnabeltier
DELETE c1 FROM contacts c1
INNER JOIN contacts c2
WHERE
c1.id > c2.id AND
c1.email = c2.email;DELETE FROM FriendsData WHERE fID
NOT IN ( SELECT fID FROM FriendsData
GROUP BY UserID, FriendsUserID, IsSpecial, CreatedBy)
DELETE
FROM
`tbl_job_title`
WHERE id NOT IN
(SELECT
*
FROM
(SELECT
MAX(id)
FROM
`tbl_job_title`
GROUP BY NAME) tbl)