多对多查询mysql

Question

I have 3 tables: users

+-----+--------+
| id  |  name  |
+-----+--------+
|  1  |  John  |
+-----+--------+
|  2  |  Mike  |
+-----+--------+

files

+-----+--------+
|  id |  file  |
+-----+--------+
|  22 | file1  |
+-----+--------+
|  23 | file2  |
+-----+--------+

and table relationship usersfiles

+-------+--------+
| usrID | fileID |
+-------+--------+
|   1   |   22   |
+-------+--------+
|   2   |   22   |
+-------+--------+
|   2   |   23   |
+-------+--------+

How should the mysql query for this question look like?

Select all files enabled for current user. Answer for this example would look like this: for user John enabled just file1 . For user Mike enabled files file1 and file2 .

Answer 1

这是一个简单的联接：

select files.id from users join usersfile on users.id=usrid join files on fileID=files.id where userid= <userid>

Answer 2

用这个

SELECT name, file FROM users,userfiles, files WHERE users.id = userfiles.usrid AND usersfiles.fileid = files.id;