Delete only join record between tables in Rails 4

Question

I have 3 Rails models as:

class User < ActiveRecord::Base
  has_and_belongs_to_many :char_factors
end

class CharFactor < ActiveRecord::Base
  has_and_belongs_to_many :users
end

class UserCharFact < ActiveRecord::Base
  belongs_to :user
  belongs_to :char_factor
end

In the above User and CharFactor models are joined through the UserCharFact model.

I'm creating new relations as:

def create
  @user_character = UserCharFact.create({:user_id => @user.id, :char_factor_id => factor_id.id})
end

And the above seems to be working properly. But I can't find a way to delete a specific join relation between 2 tables. I tried the following:

def destroy
  @user_character = CharFactor.find(params[:id])
  @user.char_factors.delete(@user_character)
end

But it actually deletes the value from CharFactor table rather than just deleting the association

Answer 1

You delete it just like you delete any other model records.

user_char_factor = UserCharFactor.find_by(user_id: user_id, char_factor_id: char_factor_id)
user_char_factor.destroy if user_char_factor

Answer 2

UserCharFact.where(char_factor_id: params[:id], user_id: @user.id).destroy_all