Mysql Query来获取用户以及所有以下用户？

Question

I'm building a app where a users can follow 'n' number of intrests.here I need to fetch the users who and all following a each intrest.for your information i have three tables as bellow

1)tbl_intrestmaster(master table for intrests)

2)tbl_users(master table)

3)tbl_userintrests(fk to tbl_intrestmaster and tbl_user)

I can do it but without processing in programming language i want to achieve this ie by using mysql query only.

Answer 1

So, tbl_userintrests (interest?) is a join table between users and interests? And, you're trying to get users who follow each interest? Ok, something like this:

SELECT u.name, i.name
FROM tbl_userintrests ui
JOIN tbl_users u
ON u.id = ui.user_id
JOIN tbl_intrestmaster i
ON i.id = ui.interst_id

So you're basically saying:

Give me everything in the join table Match users onto it Match interests onto it Now you should be left with users matching interests

For the record, this is a very simple join table question and you may find some value in searching SO / Google for other join table examples.