MySQL删除重复的行

DELETe FROM comments c1WHERe EXISTS (    SELECt *     FROM comments c2     WHERe c2.id <> c1.id         AND c2.name = c1.name         AND c2.email = c1.email         AND c2.comment = c1.comment)AND c1.id <> (    SELECt MIN(c2.id)     FROM comments c2     WHERe c2.name = c1.name         AND c2.email = c1.email         AND c2.comment = c1.comment)