Question

我有两张桌子

Users(user_id, name)            

Competition(comp_id, user_id, score)

我需要选择在竞争中发生最多的user_id。我可以用max（count）来做吗？如果两个用户的出现次数相同，有没有办法获得异常？

我试过了：

SELECT MAX(numberr), USER_ID 
FROM ( 
   SELECT USER_ID, COUNT(COMP_ID) AS numberr 
   FROM COMPETITION 
   GROUP BY USER_ID
) 
GROUP BY USER_ID;

但我得到的结果是：

MAX(numberr) USER_ID   
4             1   
2             2   
6             3

Answer 1

您可以使用$('#tablebody').html(data);

完成此操作

$('#rTable').Datatable({
      paging:false,
      destroy: true
});

Answer 2

您可以使用not exists执行此操作。如果有两个用户具有相同的最大计数，则两者都会显示。

with temp as
(
   SELECT USER_ID, COUNT(COMP_ID) AS numberr 
   FROM COMPETITION GROUP BY USER_ID
) 
select *
from temp t 
where not exists (select 1 from temp where numberr > t.numberr)

SQLFiddle

Answer 3

要获得具有最大计数的多个用户，请使用RANK：

SELECT numberr, USER_ID 
FROM ( 
   SELECT USER_ID, COUNT(COMP_ID) AS numberr 
     ,RANK() OVER (PARTITION BY USER_ID ORDER BY COUNT(COMP_ID) DESC) rnk
   FROM COMPETITION 
   GROUP BY USER_ID
) dt
WHERE rnk = 1;

选择发生次数最多的

3 个答案: