navicat中查重并删除
# 查询所有重复的数据
SELECT * FROM hao123 WHERE ir_url IN
(SELECT ir_url FROM `hao123` GROUP BY ir_url having count(ir_url)>1)
# 只显示某几个字段 提高查询速度
SELECT ir_title,ir_url FROM hao123 WHERE ir_url IN
(SELECT ir_url FROM `hao123` GROUP BY ir_url having count(ir_url)>1)
# 把查询出来的重复行删除 DELETE FROM `hao123` WHERE ir_url IN (SELECT ir_url FROM (SELECT ir_url FROM `hao123` GROUP BY ir_url having count(ir_url)>1)a) AND ir_id NOT IN (SELECT * FROM (SELECT min(ir_id) FROM `hao123` GROUP BY ir_url HAVING count(ir_url)>1)b);