Question

I would love to get some help with this. I’m using php and MySQL to build a website. I currently have 3 tables, I’ll include less in the examples. Basically I have a users table, a groups table and a grouplink table. What I have is the uid from the users table.

How should I go about it in php so I could, let’s say: match users-uid to grouplink-uid, get the grouplink-gid it matches with, match grouplink-gid to groups-gid and return groups-grpname? And goes on a while loop so all group names the user is associated with are displayed.

Thanks in advance to those who will be willing to extend a hand.

users

-------
| uid |
-------
|  1  |
-------  

groups

---------------
| gid |grpname|
---------------
|  1  | grp1  |
---------------
|  2  | grp2  |
---------------

grouplink

-------------------
| glid| uid | gid |
-------------------
|  1  |  1  |  1  |
-------------------
|  2  |  1  |  2  |
-------------------

uid is fk to uid in users while gid is fk to gid in groups

Answer 1

That’s just a simple 2-way join query:

SELECT users.uid, groups.gid, groups.grpname
FROM users
INNER JOIN grouplink ON users.uid = grouplink.uid
INNER JOIN groups ON grouplink.gid = groups.gid

the actual retrieval of a joined query result is no different than a single table query – you’ve just got more fields to deal with.