访问sql查询帮助 - 足球数据库

Question

我需要创建一个查询，显示至少有一个团队参加游戏时会议的平均出勤率。

我可以获得team1的平均值没问题。 Relationships screenshot

SELECT Conference.ConferenceName, AVG(Game.Attendance) AS AVG_ATT
FROM (Conference INNER JOIN School ON Conference.[ConferenceID] = School.[ConferenceID])
INNER JOIN Game ON School.[SchoolID] = Game.[Team1]
GROUP BY Conference.ConferenceName;

我遇到的问题是将Team2添加到等式中。

Answer 1

您可以在Access SQL中使用比Table1.Field1 = Table2.Field2更复杂的JOIN表达式，但请注意，您无法在查询设计器中编辑查询。

SELECT Conference.ConferenceName, AVG(Game.Attendance) AS AVG_ATT
FROM (Conference INNER JOIN School ON Conference.[ConferenceID] = School.[ConferenceID])
INNER JOIN Game ON (
       School.[SchoolID] = Game.[Team1] 
    OR School.[SchoolID] = Game.[Team2]
  )
GROUP BY Conference.ConferenceName;

Answer 2

我改为团队表，这使查询非常容易。我喜欢Team1和team2在游戏桌内，我可能会尝试你的方法来看看它的运作情况。

game and team screenshot