Hello again, so i write my e-commerce shop cms and have some strange error:

ActiveRecord::StatementInvalid: Mysql::Error: Unknown column 'id' in 'where clause': DELETE FROM `properties` WHERE `id` = NULL

so, i have three models

Items:

class Item < ActiveRecord::Base
  has_many :properties, :dependent => :destroy
  has_many :types, :through => :property
end

Type:

class Type < ActiveRecord::Base
  has_many :properties, :dependent => :destroy
end

Properties:

class Property < ActiveRecord::Base
  belongs_to :item
  belongs_to :type
end

So, all is okay, but when i try to item.destroy() i have error =(

This is my test code:

  test "should destroy associated properties" do

    item = Item.create(:name => "Jeans")
    type = Type.create(:key => "color")
    property = Property.new
    property.item = item
    property.type = type
    property.save


    item.destroy()
  end