如何通过联接PostgreSQL中的两个表来创建视图？

Question

我是PostgreSQL新手，并且有两个这样的表：

1. Attendees(AttendeeId, Name)
2. Couples(CoupleId, AttendeeIdMan, AttendeeIdLady)

如何创建这样的视图？

Attendees_Couple(CoupleId, Name_Man, Name_Lady)

现在，我想到了类似下面的内容，但是后来我被卡住了。

CREATE VIEW Attendees_Couple AS
SELECT a."Name"
FROM "Attendees" a, "Couples" c
WHERE a."AttendeeID" = c."AttendeeIdMan"....

任何提示或帮助将不胜感激！

Answer 1

您必须两次加入Attendees：

CREATE VIEW "Attendees_Couple" AS
SELECT c."CoupleId",
       a1."Name" AS "Name_Man",
       a2."Name" AS "Name_Lady"
FROM "Couples" AS c
   JOIN "Attendees" AS a1 ON c."AttendeeIdMan"  = a1."AttendeeId"
   JOIN "Attendees" AS a2 ON c."AttendeeIdLady" = a2."AttendeeId";

帮个忙，并使用小写字母名称！