close
1.從ptt看到選取每個學生日期最新的成績的問題
select * from x b inner join (select max(date)as date,name from x GROUP BY name ) c on b.date=c.date and b.name=c.name
不能單獨 select max(date),name,score from x group by name score會出錯
先選最新時間，如果有重複的時間選最高成績，那就
select b.name,max(score),max(date) from x b inner join (select max(date) as date,name from x GROUP BY name ) c using(date) group by b.name
max(date)為了配合group by 而用
全站熱搜
留言列表
