CODEWITHSUNDEEP
ruby-on-railsactiverecordrelationship
Eric Koslow
Eric Koslow

Reputation: 2064

HABTM relationship with custom relationship names

I'm trying to create a HABTM relationship between to classes User and Benefit. The problem is that users and benefits have multiple relationships with each other, so I'm trying to give this relationship a unique name, FavoriteBenefitization.

Unfortunately when I do User.last.favorite_benefits I keep getting the error message:

ActiveRecord::StatementInvalid: Mysql2::Error: Unknown column 'favorite_benefitizations.user_id' in 'where clause': SELECT `benefits`.* FROM `benefits` INNER JOIN `favorite_benefitizations` ON `benefits`.`id` = `favorite_benefitizations`.`favorite_benefit_id` WHERE `favorite_benefitizations`.`user_id` = 6088

Here is the code I used:

class FavoriteBenefitization < ActiveRecord::Base

  belongs_to :favorited_user, :class_name => 'User'
  belongs_to :favorite_benefit, :class_name => 'Benefit'

  validates :favorited_user, :favorite_benefit, :presence => true
end

class User < ActiveRecord::Base
  has_many :favorite_benefitizations,
    :dependent => :destroy

  has_many :favorite_benefits,
    :through => :favorite_benefitizations
end

class Beneift < ActiveRecord::Base
  has_many :favorite_benefitizations,
    :dependent => :destroy

  has_many :favorited_users,
    :through => :favorite_benefitizations
end

This is for an application running Rails 3.1

Any help would be awesome. Thank you!

Upvotes: 1

Views: 669

Answers (1)

Stone
Stone

Reputation: 2668

FavoriteBenefitization is a join table here and as such you should use user_id and benefit_id as the column names. In your other models you can do fancy things like renaming associations, scopes, or creating new ones by identifying foreign keys and classes, etc.

for example, I have this in my Message model: has_one :recipient, :foreign_key => "id", :primary_key => "receiver_id", :class_name => "User"

But Rails expects the join table columns to conform to it's expectations.

Edit: Rails expects this because you are using :through which identifies a join table.

Upvotes: 1

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