Question

我有2个SELECT查询，一个用于检索团队，另一个用于计算该团队中有多少玩家。如何将计数查询添加到第一个数据选择查询？我已经尝试过工会，但由于它们没有相同的列数而无法工作。

SELECT Subteams.id, Teams.name, Games.name as 'game' 
FROM Subteams, Games, Teams 
WHERE Subteams.gameId = Games.id 
    AND Subteams.teamId = Teams.id


SELECT COUNT(Players.subTeamId) as 'count' 
FROM Subteams, Games, Teams, Players 
WHERE Subteams.gameId = Games.id 
    AND Subteams.teamId = Teams.id 
    AND Players.subTeamId = Subteams.id 
ORDER BY Players.id

Answer 1

只需将其他表中的列添加到COUNT()查询。

SELECT Subteams.id, Teams.name, Games.name as game, COUNT(Players.subTeamId) as 'count' 
FROM Subteams
JOIN Games ON Subteams.gameId = Games.id
JOIN Teams ON Subteams.teamId = Teams.id
LEFT JOIN Players ON Players.subTeamId = Subteams.id 
GROUP BY Subteams.id
ORDER BY Subteams.id

我还使用了LEFT JOIN，因此对于没有玩家的球队，您将获得0。

将count列添加到现有的Select Query

1 个答案: