# Schema and relationships between tables **URL:** \ **Category:** Rails\ **Created:** [November 7, 2008, 6:51pm UTC](https://www.ruby-forum.com/t/schema-and-relationships-between-tables/152820 "2008-11-07T18:51:43Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![snantz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/c2a13f/32.png) [@snantz](https://www.ruby-forum.com/u/snantz)\ **Post date:** [November 7, 2008, 6:51pm UTC](https://www.ruby-forum.com/t/schema-and-relationships-between-tables/152820/1 "2008-11-07T18:51:43Z")
I am trying to allow a user to answer some questions and then save those questions but I am unsure if I am getting the layout correct. Here is what I have so far: There is a questions table holding the questions to ask There is an answers tables which holds the answers to the questions asked of a user. Then there is of course the Users table which hold a variety of user info I figure my migrations would look something like: Questions: has\_many :answers Answers: belong\_to :user, belongs\_to :question User has\_many :answers so my table would look like: User: id, username, . . . Questions: id, question Answer: id, user\_id, question\_id, answer Where I am a little confused is if the belongs\_to :question should rather be a has\_one :question and would that change the schema at all? Also, can anyone point me to some good online tutorials involving Model Relationships, thanks, -S ---
**Author:** ![snantz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/c2a13f/32.png) [@snantz](https://www.ruby-forum.com/u/snantz)\ **Post date:** [November 7, 2008, 8:30pm UTC](https://www.ruby-forum.com/t/schema-and-relationships-between-tables/152820/2 "2008-11-07T20:30:33Z")
When you “belong\_to” it means that the foreing key is at your side, you belong to the question 'cos you wouldn’t be able to exist without it, there’s no reason to have a question without a user or an answer. A has\_one means that you have of of that, but you usually don’t need it to exist. it also means that the foreign key lives at the other side. Look for weak and strong entities in database design - Maurício Linhares [http://alinhavado.wordpress.com/](http://alinhavado.wordpress.com/) (pt-br) | [http://blog.codevader.com/](http://blog.codevader.com/) (en) João Pessoa, PB, +55 83 8867-7208 On Fri, Nov 7, 2008 at 2:51 PM, Shandy N. ---
**Author:** ![snantz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/c2a13f/32.png) [@snantz](https://www.ruby-forum.com/u/snantz)\ **Post date:** [November 7, 2008, 10:15pm UTC](https://www.ruby-forum.com/t/schema-and-relationships-between-tables/152820/3 "2008-11-07T22:15:50Z")
Shandy N. wrote: > I am trying to allow a user to answer some questions and then save those > questions but I am unsure if I am getting the layout correct. Here is > what I have so far: > > There is a questions table holding the questions to ask > > There is an answers tables which holds the answers to the questions > asked of a user. > > Then there is of course the Users table which hold a variety of user > info > > I figure my migrations would look something like: > > Questions: has\_many :answers > > Answers: belong\_to :user, belongs\_to :question > > User has\_many :answers > > so my table would look like: > > User: id, username, . . . > > Questions: id, question > > Answer: id, user\_id, question\_id, answer > > Where I am a little confused is if the belongs\_to :question should > rather be a has\_one :question and would that change the schema at all? > Also, can anyone point me to some good online tutorials involving Model > Relationships, thanks, > > -S For what it’s worth, I would probably do something like: User: has\_many :questions has\_many :answers Question: has\_many :answers belongs\_to :user Answer: belongs\_to :question belongs\_to :user Tables: User: id | user\_name Question: id | user\_id | question Answer: id | user\_id | question\_id | answer hope this helps