mysql中删除重复记录

原文链接：http://blog.csdn.net/dsiori/article/details/52806709

DELETE FROM user WHERE id NOT IN(SELECT * FROM(SELECT id FROM user GROUP BY username)AS b)

DELETE FROM rf_data_tuchong_tag WHERE tag_id IN ( SELECT tag_id FROM ( SELECT tag_id, min( id ) id, count() num FROM rf_data_tuchong_tag GROUP BY tag_id HAVING num > 1 ) a ) AND id NOT IN ( SELECT id FROM ( SELECT tag_id, min( id ) id, count() num FROM rf_data_tuchong_tag GROUP BY tag_id HAVING num > 1 ) b )

DELETE
FROM
    love_tc_post
WHERE
    post_id IN (
    SELECT
        post_id
    FROM
        ( SELECT post_id, min( id ) id, count(*) num FROM love_tc_post GROUP BY post_id HAVING num > 1 ) a
    )
    AND id NOT IN (
    SELECT
        id
    FROM
    ( SELECT post_id, min( id ) id, count(*) num FROM love_tc_post GROUP BY post_id HAVING num > 1 ) b
    )