仅删除 Rails 4 中表之间的连接记录

Question

我有 3 个 Rails 模型：

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

上面的User和CharFactor模型是通过UserCharFact模型连接起来的。

我正在建立新的关系：

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

以上似乎工作正常。但是我找不到在 2 table 秒之间删除特定 join relation 的方法。我尝试了以下方法：

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

但它实际上是从 CharFactor table 中删除值，而不是仅仅删除关联

Answer 1

就像删除任何其他模型记录一样删除它。

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

仅删除 Rails 4 中表之间的连接记录

Delete only join record between tables in Rails 4

mysql

ruby-on-rails

ruby

ruby-on-rails-4

has-and-belongs-to-many