返回 null 的 MySQL 计数(列)

Question

我有 3 张 table :

• 球队(id_team、名称、id_season)
• Teams_Stats(id_stats、id_game、id_team、胜利、失败)
• 赛季(id_season、名称、nbr_teams)

我试图找出每个球队在特定赛季(本例中为 2015 年)的胜利次数。

这就是我到目前为止所拥有的，但它对所有团队都返回 0。

我的 SQL 语法:

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

我做错了什么？

谢谢:)

Answer 1

尝试修改您的查询，类似于

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