Question

http://www.sqlfiddle.com/#!3/7a295/1

我在visual studio 10中有一个ms sql数据库，我需要一个查询帮助，从收藏夹表中获取最想要的游戏以及游戏表中的游戏cover_img。我有查询使用第一部分： -

SELECT game_name, 
       game_platform, 
       Count(game_name) AS Expr1 
FROM   favourites 
GROUP  BY game_name, 
          game_platform 
HAVING ( Count(game_name) = (SELECT Max(mycount) AS Expr1 
                             FROM   (SELECT game_name, 
                                            Count(game_name) AS mycount 
                                     FROM   favourites AS Favourites_1 
                                     GROUP  BY game_name) AS derivedtbl_1) );

但是我无法让cover_img与游戏桌上的最大游戏相匹配，有人可以帮助我，这是我到目前为止所做的，但它不起作用： -

SELECT favourites.game_name, 
       favourites.game_platform, 
       games.cover_img, 
       Count(favourites.game_name) AS Expr1 
FROM   games 
       inner join favourites 
               ON games.name = favourites.game_name 
GROUP  BY favourites.game_name, 
          favourites.game_platform, 
          games.cover_img HAVING (Count(favourites.game_name) = (SELECT 
                                 Max(mycount) AS Expr1 
                                                                FROM 
                                 (SELECT game_name, 
                                         Count(game_name) AS mycount 
                                  FROM   favourites AS Favourites_1 
                                  GROUP  BY game_name) AS derivedtbl_1));

Answer 1

您可以将问题分成较小的部分：

;
WITH    Games       AS
(
        SELECT  *
        FROM    (   VALUES
                    ('Pacman', 'Atari', 'A'),
                    ('Enduro', 'Atari', 'B'),
                    ('River Raid', 'Atari', 'C')
                ) AS X (Name, [Platform], cover_img)    
),      Favourites  AS
(
        SELECT  *
        FROM    (   VALUES
                    ('Pacman', 'Atari'),
                    ('Pacman', 'Atari'),
                    ('Pacman', 'Atari'),
                    ('Enduro', 'Atari')
                ) AS Y (game_name, game_platform)   
),      MostWanted  AS
(   --  Identify the most wanted game, per platform
        SELECT      game_name, game_platform, COUNT(*) Total,
                    ROW_NUMBER() OVER
                    (
                        PARTITION BY /*game_name,*/ game_platform
                        ORDER BY COUNT(*) DESC
                    ) [Order]
        FROM        Favourites
        GROUP BY    game_name, game_platform
)
SELECT  MostWanted.*, Games.cover_img
FROM    MostWanted
JOIN    Games       -- JOIN that with games table to get more details
    ON  MostWanted.game_name = Games.Name
WHERE   MostWanted.[Order] = 1  -- Only the first most wanted

Answer 2

您的第一个查询将选择您要查找的游戏。

   SELECT game_name, 
           game_platform, 
           Count(game_name) AS Expr1 
    FROM   favourites 
    GROUP  BY game_name, 
              game_platform 
    HAVING ( Count(game_name) = (SELECT Max(mycount) AS Expr1 
                                 FROM   (SELECT game_name, 
                                                Count(game_name) AS mycount 
                                         FROM   favourites AS Favourites_1 
                                         GROUP  BY game_name) AS derivedtbl_1) );

现在你需要的是一个包装器查询来查找与这些游戏相关的所有图像。

SELECT xx.game_name,xx.game_platform, games.cover_img
from
(SELECT game_name, 
        game_platform 
 FROM   favourites 
 GROUP  BY game_name, 
           game_platform 
 HAVING ( Count(game_name) = (SELECT Max(mycount) AS Expr1 
                              FROM   (SELECT game_name, 
                                      Count(game_name) AS mycount 
                                      FROM   favourites AS Favourites_1 
                                      GROUP  BY game_name) AS derivedtbl_1
                                     ) 
                             )
) xx
join games on games.game_name=xx.game_name 
     and games.game_platform=xx.game_platform

试一试。

Answer 3

这样做你想要的吗？

SELECT TOP 1 f.game_name, f.game_platform, g.cover_img, 
       Count(f.game_name) as cnt
FROM   games g inner join
       favourites f
       ON g.name = f.game_name 
GROUP BY f.game_name, f.game_platform, g.cover_img
ORDER BY Count(f.game_name) desc;

SQL Query获取最想要的游戏细节

3 个答案: