加入四个表

Question

我有我想知道如果我要加入三个表，该表的结构如下：

members               

member_id login  


permissions 

K_id member_id date 


kcontent 

K_id id content 


ktitle 

K_id   title 

我想要做的是，对特定的成员（member_id ）....获得每个成员链接到的每个K_id，按日期DESC排序，然后从kcontent中获取由id和标题排序的内容ktitle

Answer 1

是的，您应该。

尝试沿着这些路线的东西：

SELECT a.member_id, b.date, d.title, c.content 
FROM members as a 
JOIN permissions as b 
ON b.member_id = a.member_id 
JOIN kcontent as c 
ON c.k_id = b.k_id 
JOIN ktitle as d 
ON d.k_id = b.k_id 
WHERE a.member_id = {inputMemberId} 
ORDER BY b.date, d.k_id, d.title 

Answer 2

SELECT * 
FROM 
PERMISSIONS INNER JOIN KCONTENT 
ON PERMISSIONS.K_ID = KCONTENT.K_ID 
INNER JOIN KTITLE 
ON KCONTENT.K_ID = KTITLE.K_ID 
INNER JOIN MEMEBRS 
ON MEMBERS.MEMBER_ID = PERMISSIONS.MEMBER_ID 
WHERE MEMBERS.MEMBER_ID = ### 
ORDER BY PERMISSIONS.DATE, MEMBERS.MEMBER_ID