三个表并获取与中间字段连接的字段

Question

我有三个表T1，T2和T3以及以下列。

T1: a, b
T2 b, c
T3 c,d

我想创建一个名为T4的视图，其中包含字段a，d

如何编写查询来执行此操作？

Answer 1

您可以像这样加入他们：

CREATE VIEW T4 AS 
SELECT T1.a, T3.d
FROM T1 
JOIN T2 ON T1.b = T2.b
JOIN T3 ON T2.c = T3.c

See this SQLFiddle

Answer 2

试试这个::

CREATE VIEW T4
AS
SELECT 
T1.a, 
T3.d
FROM T1 
INNER JOIN T2 ON T1.b = T2.b
INNER JOIN T3 ON T2.c = T3.c