Active Record Querying HABTM

Rails
1

I am new to rails and stuck on one Querying issue. Here is the
situation.

Model: Category
class Category < ActiveRecord::Base
has_and_belongs_to_many :postings
has_and_belongs_to_many :volunteers
end

Model: Posting
class Posting < ActiveRecord::Base
has_and_belongs_to_many :categories
end

Model: Volunteer
class Volunteer < ActiveRecord::Base
has_and_belongs_to_many :categories
end

Now Here is the problem I am trying to solve

I want to find out all the postings of the categories that the
volunteer is interested in. The volunteer might be interested in more
than one categories and posting might be assigned more than one
categories.

Here is the basic pseudocode

vol=Volunteer.find 1
vol_cats=vol.categories
foreach(vol_cat in vol_cats)
{
postings=postings + vol_cat.postings
}

Please Help me

Thank you

2

On Mon, Jun 11, 2012 at 12:04 PM, saroj s. [email protected] wrote:

I want to find out all the postings of the categories that the
volunteer is interested in.

Sounds like you want a “has_many :through” relationship.

-Dave

–
Dave A., Cleared/Remote Ruby on Rails Freelancer
(NoVa/DC/Remote); see www.DaveAronson.com, and blogs at
www.Codosaur.us, www.Dare2XL.com, www.RecruitingRants.com

3

Solution: