幽灵资源网 Design By www.bzswh.com
1.查找重复的行
SELECT * FROM blog_user_relation a WHERE (a.account_instance_id,a.follow_account_instance_id) IN (SELECT account_instance_id,follow_account_instance_id FROM blog_user_relation GROUP BY account_instance_id, follow_account_instance_id HAVING COUNT(*) > 1)
2.删除重复的行(保留一条)
PS:因为mysql的delete,如果被删的表的where条件里有in,且in里面也有此表,那就删除不了。
/*创建个临时表*/ CREATE TABLE blog_user_relation_temp AS ( SELECT * FROM blog_user_relation a WHERE (a.account_instance_id,a.follow_account_instance_id) IN ( SELECT account_instance_id,follow_account_instance_id FROM blog_user_relation GROUP BY account_instance_id, follow_account_instance_id HAVING COUNT(*) > 1) AND relation_id NOT IN (SELECT MIN(relation_id) FROM blog_user_relation GROUP BY account_instance_id, follow_account_instance_id HAVING COUNT(*)>1)); /*删除数据*/ DELETE FROM `blog_user_relation` WHERE relation_id IN (SELECT relation_id FROM blog_user_relation_temp); /*删除临时表*/ DROP TABLE blog_user_relation_temp;
标签:
Mysql,查询,删除,重复的行
幽灵资源网 Design By www.bzswh.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站文章均来自网站采集或用户投稿,网站不提供任何软件下载或自行开发的软件! 如有用户或公司发现本站内容信息存在侵权行为,请邮件告知! 858582#qq.com
免责声明:本站文章均来自网站采集或用户投稿,网站不提供任何软件下载或自行开发的软件! 如有用户或公司发现本站内容信息存在侵权行为,请邮件告知! 858582#qq.com
幽灵资源网 Design By www.bzswh.com
暂无评论...