mysql去重

mysql查询重复 SELECT url, COUNT(*) AS occurrences FROM policy_web_list GROUP BY url HAVING occurrences > 1;

删除重复 DELETE FROM policy_web_list WHERE id IN ( SELECT sub.id FROM ( SELECT id, url, ROW_NUMBER() OVER (PARTITION BY url ORDER BY id) AS row_num FROM policy_web_list ) AS sub WHERE sub.row_num > 1 );