mysql查询,它输出一个显示计数的数据表


mysql query that outputs a table of data showing count

我已经对此进行了研究,但还没有找到答案,所以我认为这里有人可以提供一些线索。我试图创建一个返回的数据表,显示每个用户按周数分组选择的游戏数量。

数据库结构:

id  |  user   |   team    | week_number
----+---------+-----------+-------------
1   |  john   |  eagles   |  1 
2   |  john   |  saints   |  1 
3   |  harry  |  patriots |  1 
4   |  frank  |  cowboys  |  1
5   |  john   |  falcons  |  2
6   |  frank  |  cardinals|  2

所需输出:

week_number | frank | harry | john
------------+-------+-------+-------
     1      |    1  |    1  |   2
     2      |    1  |    0  |   1

我将使用PHP来显示输出。

您想要的输出的替代方案可以是:

WEEK_NUMBER USER    GAMES  
1          frank    1  
1          harry    1  
1          john     2  
2          frank    1  
2          john     1  

如果这个输出可以为您工作,那么您可以运行以下查询:

select week_number,user,count(team) as games from table 
group by week_number,user;

在撞墙之后,我得到了启发,终于得到了查询。;)

你可以运行这个来实现你想要的输出:

SELECT  T.week_number,
        IFNULL(SUM((CASE WHEN T.user = 'frank' THEN T.games END)),0) frank,
        IFNULL(SUM((CASE WHEN T.user = 'harry' THEN T.games END)),0) harry,
        IFNULL(SUM((CASE WHEN T.user = 'john' THEN T.games END)),0) john
FROM    (select week_number,user,count(team) as games from table_name group by week_number,user) as T
GROUP BY week_number

演示