mysql 去除多個重複資料的sql語句(真實有效)
阿新 • • 發佈:2020-12-25
問題描述:
mysql某張表中存在多個重複資料,目的去重;
demo表:
原因分析:
在做爬蟲時,針對重複資料已經入庫,想使用個簡單的sql直接去重。
解決方案:
delete from demo where title in (select bt from (select demo.title bt from demo group by demo.title having COUNT(demo.title)>1) as t)
and id not in (select mid from(select min(id) mid from demo group by title having count(demo.title)>1) as tt)
最後好好琢磨一下掌握就可以了;