每天從數據庫中玩遊戲的用戶數

Question

我有一個用遊戲表的小遊戲數據庫答案： 每個用戶每天可以玩和回答最多2次， 表答案是這樣結構化的：

UID | ANSWER | DATE

我願做一個查詢來獲取多少用戶玩，每天至少一次。 我做了這樣的事情，但這不起作用。

SELECT Day(date) as n, 
     Dayname(date) as m, 
     uid,    
     COUNT(uid) as c 
FROM answers 
WHERE Year(date) = '2012' 
GROUP BY uid HAVING count(*) <=2 //COUNT user who played at least 2 times per day 
GROUP BY n //group by day 
ORDER BY n 

，我想有這樣的結果：

Friday | 9-5-2012 | 1254

Saturday | 10-5-2012 | 1427 ...

讚賞任何幫助...

Answer 1

而不是兩個group by子句，使用一天中的一組：

select day(date) as d 
,  month(date) as m 
,  count(distinct uid) as c 
from answers 
where year(date) = '2012' 
group by 
     day(date) 
,  month(date) 
having count(*) > 1