has_many through - how to use middle model's info?

rubyonrails-talk
1

Hey,

How can I use the information in the "middle" table of a :has_many through relationship? Here's an example:

Club and Student have a :has_many through relationship with each other.

class Club < ActiveRecord::Base   has_many :memberships, :dependent => :destroy   has_many :students, :through => :memberships end

class Student < ActiveRecord::Base   has_many :memberships, :dependent => :destroy   has_many :clubs, :through => :memberships end

# middle model class Membership < ActiveRecord::Base   belongs_to :student   belongs_to :club end

Here is the table for "memberships" id - integer club_id - integer student_id - integer joined_on - datetime

If I have @club_id, and I want to find all students that joined that club on a certain date, how can I do that?

How can I do something like this Club.find_by_id(@club_id, :include => :students) and specify the "joined_on" date?

Thanks for any help.

2

To get the memberships, you can:

@memberships = @club.memberships.all(:conditions => {:created_on => date})

Then now you simply have to get the students of each membership.