结合3 SQL SELECT到一个语句

Question

我有3个表：

• 队（id_team，名称，id_season）
• 四季（id_season，名称，nbr_teams）
• Teams_Stats（id_stats，id_game，id_team ，胜利，失败，平局）

我有3个查询正在工作的单独精确：

SELECT T.name, count(TS.victory) as Wins 
FROM Teams T 
JOIN Seasons S ON T.id_season = S.id_season AND S.name = '2015' 
LEFT JOIN Teams_Stats TS ON TS.id_team = T.id_team AND TS.victory = 1 
GROUP BY T.name 
ORDER BY T.name 

SELECT T.name, count(TS.defeat) as Losses 
FROM Teams T 
JOIN Seasons S ON T.id_season = S.id_season AND S.name = '2015' 
LEFT JOIN Teams_Stats TS ON TS.id_team = T.id_team AND TS.defeat = 1 
GROUP BY T.name 
ORDER BY T.name 

SELECT T.name, count(TS.victory) as Draws 
FROM Teams T 
JOIN Seasons S ON T.id_season = S.id_season AND S.name = '2015' 
LEFT JOIN Teams_Stats TS ON TS.id_team = T.id_team AND TS.draw = 1 
GROUP BY T.name 
ORDER BY T.name 

我想知道如何才能得到相同的结果，但只有1个查询。我无法得到它？也许有人可以抛出一些光...

我明白，

谢谢。

Answer 1

可以使用条件汇总：

SELECT T.name, 
     sum(TS.victory=1) as Wins, 
     sum(TS.defeat=1) as Losses, 
     sum(TS.draw =1) as Draws 
FROM Teams T 
JOIN Seasons S ON T.id_season = S.id_season AND S.name = '2015' 
LEFT JOIN Teams_Stats TS ON TS.id_team = T.id_team 
GROUP BY T.name 
ORDER BY T.name 

Demo here