mysql - (A 加入 B) 加入 (C 加入 D)

Question

我想对 JOIN 进行特定的排序

SELECT *
FROM (lives_in as t1 NATURAL JOIN preferences p1) l1
JOIN (lives_in t2 NATURAL JOIN preferences p2) l2
ON l1.dormid = l2.dormid

返回错误。

有人可以帮忙吗？非常感谢!

Answer 1

您的别名查询缺少 SELECT 子句，所以试试这个:

SELECT *
FROM (
    select * -- added this
    FROM lives_in as t1
    NATURAL JOIN preferences p1) l1
JOIN (
    select * -- added this
    FROM lives_in t2
    NATURAL JOIN preferences p2) l2
ON l1.dormid = l2.dormid