SQL:如何从一个表中选择另一个表中的不同值？

Question

我有两张 table

表“Teams”有两列

teamID,
teamName

表“匹配”有三列

matchID, 
teamID_1,
teamID_2

...如下图所示:

如何构造一个 select 语句，该语句将通过 Teams.teamName 拉取 Match.teamID_1 和 Match.teamID_2基于他们各自的ID？

我只能对一列或另一列执行此操作，但不能同时对两列执行此操作:

SELECT Match.matchID, Teams.teamName
    FROM Match
    INNER JOIN Teams ON Match.teamID_1 = Teams.teamID

或者

SELECT Match.matchID, Teams.teamName
    FROM Match
    INNER JOIN Teams ON Match.teamID_2 = Teams.teamID

Answer 1

您可以多次加入同一个表。只需为它们添加别名(t1 和 t2 如下所示):

SELECT 
    Match.matchID, 
    t1.teamName, 
    t2.teamName
FROM Match
    INNER JOIN Teams t1 ON Match.teamID_1 = t1.teamID
    INNER JOIN Teams t2 ON Match.teamID_2 = t2.teamID