sqlite 的去重

1） 找到重複的記錄，歸類到一個新表裏面 max(id) 是想要刪除的record

create table ttt as select gallery_url ,max(id) as theid from gallery group by gallery_url having count(*) >=2

 

2） 刪除

delete from gallery where id in ( select theid from ttt)