INNER JOIN第三张表

Question

这是代码

SELECT profile_friends.friends_friend_id,
       members.name,
       profile_friends.friends_member_id,
       members.member_id
FROM profile_friends
INNER JOIN members ON profile_friends.friends_friend_id=members.member_id

如何将第三个表和行添加到此

profile_portal pp_main_photo

Answer 1

在jour语句中添加第二个连接。

SELECT profile_friends.friends_friend_id, members.name, profile_friends.friends_member_id,members.member_id,pp_main_photo
FROM profile_friends
INNER JOIN members
ON profile_friends.friends_friend_id=members.member_id
INNER JOIN profile_portal on <condition>

Answer 2

 INNER JOIN profile_portal ON <YOUR CONDITIONS>

关于错误： $ res没有结果集中的数据。所以请检查查询是否返回值。