Question

我正在编写一个应用程序以保持飞镖得分。我已经创建了一个关系数据库，如下所示：

GameInformation gameId | numberOfPlayer | totalInnings |游戏类型
0 | 2 | 13 | 0
1 | 2 | 14 | 0
2 | 2 | 20 | 0
3 | 3 | 16 | 0

PlayersByGame gameId | playerId |局| MPR
0 | 0 | 13 | 1.538
0 | 1 | 13 | 1.651
1 | 0 | 14 | 1.500
1 | 1 | 14 | 2.012
2 | 0 | 20 | 1.658
2 | 2 | 20 | 2.123
3 | 2 | 16 | 2.001
3 | 1 | 16 | 1.325
3 | 0 | 16 | 1.001

球员
名称|标识
Dainon | 0
安迪| 1
基思| 2个

我熟悉简单的SQL查询，但不知道如何获得玩家（Dainon）与玩家（Andy）玩过的游戏数量，而没有超过2名玩家的游戏，只有Dainon和安迪互相对抗。在查询时，我同时拥有Dainon和Andy的玩家ID。

任何人都可以提供任何有关如何编写SELECT语句的见解。

我开始使用错误的查询，例如：

SELECT * FROM PlayersByGame WHERE playerId LIKE 0 and playerId LIKE 1;


SELECT gameId, numberOfPlayers, totalInnings, gameType
FROM GameInformation
WHERE (numberOfPlayers = 2)
UNION
SELECT gameId, playerId, innings, mpr
FROM PlayersByGame
WHERE (playerId = 0)
UNION
SELECT gameId, playerId, innings, mpr
FROM PlayersByGame AS PlayersByGame_1
WHERE (playerId = 1)

谢谢，感谢您的任何帮助！

Answer 1

我会尝试类似的东西（未经测试）

SELECT count(gi.id)
FROM GameInformation gi
JOIN PlayersByGame pbg1 ON pbg1.gameId=gi.id AND pbg1.playerId = {idPlayer1}
JOIN PlayersByGame pbg2 ON pbg2.gameId=gi.id AND pbg2.playerId = {idPlayer2}
WHERE gi.numberOfPlayer = 2

Answer 2

试试这个。点击她查看Sqlfiddle版本

select count(*) as NumOfGames
from
(
select gameid,count(*)
from 
(
    select gameId,playerId
    from PlayersByGame
    where gameId in
    (
        SELECT gameId from GameInformation
        where numberOfPlayer =2
    )
    AND
    playerId in
    (
        select id from Players
        where Name in('Dainon','Andy')
    ) 
) as A
group by A.gameId
having count(*) =2
) as B

SQL如何从关系数据库中的游戏中获取玩家VS玩家游戏数

2 个答案: