CODEWITHSUNDEEP
ruby-on-railsactiverecord
Danny Santos
Danny Santos

Reputation: 1160

Activerecord asociation not working on friend system

I'm trying to test out a Facebook-style friend system. I have a simple User model and a UserRelationship model that takes two foreign keys from the users table, which I've named inviter_id and invited_id:

class User < ApplicationRecord
  has_many :user_relationships
  has_many :friends, through: :user_relationships, source: :invited
end

class UserRelationship < ApplicationRecord
  belongs_to :inviter, class_name: "User"
  belongs_to :invited, class_name: "User"
end

I've tried variations of this and I can't figure out where I'm going wrong. I want to be able to call User.first.friends and get a full friends list. currently the error I'm getting is:

ActiveRecord::StatementInvalid: PG::UndefinedColumn: ERROR:  column user_relationships.user_id does not exist

The tables:

create_table "user_relationships", force: :cascade do |t|
  t.integer  "inviter_id"
  t.integer  "invited_id"
  t.datetime "created_at", null: false
  t.datetime "updated_at", null: false
end

create_table "users", force: :cascade do |t|
  t.string   "name"
  t.string   "email"
  t.datetime "created_at", null: false
  t.datetime "updated_at", null: false
end

Thanks

UPDATE

Using what Abhilash said about the has_many :user_relationships association I changed it to this:

class User < ApplicationRecord
  has_many :user_relationships, foreign_key: "invited_id"
  has_many :friends, through: :user_relationships, source: :invited
end

The problem is that that only returns the inviteds, not the inviters. I feel like there should be a way to get both using the database and associations?

Upvotes: 0

Views: 29

Answers (1)

Abhilash Reddy
Abhilash Reddy

Reputation: 1549

You need to remove the below line from the User model.

has_many :user_relationships

Because in the UserRelationship model you've fields for inviter_id and invited_id but not user_id.

So you can have a method like this in your model to get user_relationships for a given user.

def user_relationships
    UserRelationship.where("invited_id = ? OR inviter_id = ?", self.id, self.id)
end

Edited:

You can also have associations like below:

class User < ActiveRecord::Base
  has_many :inviter_user_relationships, :class_name => 'UserRelationship', :foreign_key => 'inviter_id'
  has_many :invited_user_relationships, :class_name => 'UserRelationship', :foreign_key => 'invited_id'

  def user_relationships
    inviter_user_relationships + invited_user_relationships
  end

end

Upvotes: 1

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