What is the RoR Way for this "find"?

rubyonrails-talk
1

Ryan Bigg wrote:

Please use "real" names in your examples as it helps us to provide more accurate information. For example, I don't know what kind of association table2 has with table1, so I've treated it as a belongs_to.

Here's what I have for my code.

Users Committees

I want to find all of the active users and then from there, get all of the committees that each person is on.

So do I need to set up the has_many and belongs_to relationships for these models?

Secondly, I am easily able to make the first piece of code work.

@user_list = User.find(:all, :select => "id, active", :conditions => ["active =>", true], :include => "committees")

This gives me [#<User id:1, Active: true>, #<User id:2, Active: true>, #<User id:3, Active: true>]

But I'm not able to make the second part of this work to get the list of committees for each user.

Thanks!

2

You need to relate the tables in the database, as well as in Rails.

So make sure your committees table has a user_id column. Then, a committee can belong to a user.

However, if you really have a many-to-many relationship, then a join table might work best. Check out the Rails API docs on the has_many :through option for how to set that up. In short, you create new table that relates users to committees. So once you have a user object, you can just do user.committees.

Jeff

REST with Rails Oct 4, 2008, in Austin, Texas http://www.purpleworkshops.com/workshops/rest-and-web-services

3

But I'm not able to make the second part of this work to get the list of committees for each user.

Well, of course not. :include => "committees" is going to expect that the two tables are associated, which as you mentioned they are not. How is Rails supposed to find the "committees" association of you didn't specify it?

It sounds to me like the two tables (users and committees) SHOULD be associated anyway. Is there some reason they are not?

Becca Girl wrote:

4

I have added

class User <A ctiveRecord::Base   has_many :comittees end

class Comittee < ActiveRecord::Base   belongs_to :user end

I am still unable to get the second part of the code to work.

@table2 = @table1.table2

@comittees = @user_list.committees - is this the wrong syntax?

5

In your has_many you spelt "comittees" with one m, in your syntax you spelt it with two: "committees"

6

Becca Girl wrote:

I have added

class User <A ctiveRecord::Base   has_many :comittees end

class Comittee < ActiveRecord::Base   belongs_to :user end

Should a committee be comprised of only one user? That's what you have with this. If a committee is really comprised of n users, you need to use a has_many :through. Off the side of my head, it's something like

class User     has_many :committee_members     has_many :committees, :through => :committee_members end

class Committee     has_many :committee_members     has_many :users, :through => :committee_members end

class CommitteeMember     belongs_to :committee     belongs_to :user end

Then you can go both ways. You can get a list of committees for a particular user or a list of users for a particular committee. And, since it's a has_many :through, you can put attributes on committee_members that relate specifically to that user's membership in the committee (such as is_chair or something).

Peace, Phillip