使用多个外键连接两个表

Question

表Trips

TripId_PK
StartLocationId_FK
EndLocationId_FK

表Locations

LocationId_PK
Name

如何将两个表连接两次，以便我可以获得如下数据集：

TripId_PK
StartLocationName
EndLocationName

提前致谢。

Answer 1

SELECT  t.TripId_PK, ls.name StartLocationName, le.name EndLocationName
FROM    trips t
JOIN    locations ls
ON      ls.LocationId_PK = t.StartLocationId_FK
JOIN    locations le
ON      le.LocationId_PK = t.EndLocationId_FK

Answer 2

你可以试试这个

SELECT t.TripId_PK, ls.StartLocationName, le.EndLocationName
FROM Trips t
JOIN Locations ls ON t.StartLocationId_FK = ls.LocationId_PK
JOIN Locations le ON t.EndLocationId_FK = le.LocationId_PK