# Models and multiple tables relationships

**URL:** <https://www.ruby-forum.com/t/models-and-multiple-tables-relationships/117233>\
**Category:** Rails\
**Created:** [October 15, 2007, 4:29am UTC](https://www.ruby-forum.com/t/models-and-multiple-tables-relationships/117233 "2007-10-15T04:29:40Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![eafonsof](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/9e8a1a/32.png) [@eafonsof](https://www.ruby-forum.com/u/eafonsof)\
**Post date:** [October 15, 2007, 4:29am UTC](https://www.ruby-forum.com/t/models-and-multiple-tables-relationships/117233/1 "2007-10-15T04:29:40Z")

</div>

Hi there. I’ve been researching and thinking for quite a while now but  
I’m not getting a solution in terms of models and/or table  
relationship to represent and manipulate the data the way I need.  
I thought I could bring this problem to the discussion group since  
some folks in here probably know how to solve it at the tip of their  
tongue (or fingers).

So, here’s the problem:

I have the following tables/models:

groups (id, name, etc)  
users (id, name, etc)  
talents (id, name, etc)  
events (id, name, etc)  
groups\_users(group\_id, user\_id) : groups habtm users; users habtm  
groups

- Each group has many users; each user belongs to many groups.  
talents\_users(talent\_id, user\_id) : talents habtm users; users habtm  
talents
- Each user has many talents; each talent belongs to many users.  
events\_groups(event\_id, group\_id)
- Each group has many events; each event belongs to many groups.

Here’s where I get confused as for how to map the extra information I  
need. I wanted to have a table of roles like the following:

roles (group\_id, user\_id, talent\_id, event\_id)

- Each group/event (in events\_groups) has many user/talent (in  
talents\_users) where user belongs to group.

I don’t know if a table like roles is a good solution for this problem  
and if so what are the necessary changes to the existing models  
(groups, users, etc) and what new models/etc need to be created (and  
how) to provide that functionality?

Here are some of the things I would like to do with that:

a) Add/delete talents/users to/from specific group/events.  
b) List the events associated to a specific group with corresponding  
talents/users for each group/event.  
c) List the events a user is associated to for a specific group  
(include the user/talents for each event).  
d) List the events a user is associated to (all groups) and include  
the specific talents.  
e) etc, etc, etc.

Thanks in advance for your help.  
Eduardo.

---

<div class="post-metadata">

**Author:** ![eafonsof](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/9e8a1a/32.png) [@eafonsof](https://www.ruby-forum.com/u/eafonsof)\
**Post date:** [October 15, 2007, 1:48pm UTC](https://www.ruby-forum.com/t/models-and-multiple-tables-relationships/117233/2 "2007-10-15T13:48:52Z")

</div>

Ah, another thing I wanted to do is this:  
e) List the users in a specific group with the corresponding group/  
events having the user (with the user/talent).