Question

我想获取每个人的最大值的行。使用MySQL。

person       page       views
John         home       20
John         cart       15
John         search     43
James        home       32
James        about      41
Kim          cart       5
Kim          contact    3

结果

Person   Page
John     search
James    about
Kim      cart

一种想法是获取MAX(views) GROUP BY PERSON然后执行IF(a.views = b.max_views, page, 0)，但这似乎需要3个步骤，并且可能有更简单的方法。

Answer 1

 Select * From table t
 where views =
     (Select Max(views) From table
      Where person = t.person)

Answer 2

您可以使用子查询来获得结果：

select t1.person, t1.page
from yt t1
inner join
(
  select max(views) maxview, person
  from yt
  group by person
) t2
  on t1.person = t2.person
  and t1.views = t2.maxview;

请参阅SQL Fiddle with Demo

Answer 3

试试这个

select 
    * 
from 
   data d
where d.views =  ( select max(views) from data d2 where d2.person = d.person )

SQL：返回每组具有最大值的行

3 个答案: