我正在努力解决对象中的错误，根本不确定问题出在哪里.
这就是模型的样子:
class Car < ActiveRecord::Base
has_many :car_colors
has_many :colors, :through => :car_colors
end
class CarColor < ActiveRecord::Base
belongs_to :color
belongs_to :car
end
class Color < ActiveRecord::Base
has_many :car_colors
has_many :cars, :through => :car_colors
end
以下是问题:
@cars = Car.all(:joins => :car_colors, :conditions => { :car_colors => {:color_id => params[:id_number]}}, :order => "cars.created_at DESC")
以及错误输出:
PG::Error: ERROR: column reference "created_at" is ambiguous
LINE 1: ...d" WHERE "car_colors"."color_id" = 2 AND (created_at...
^
: SELECT "cars".* FROM "cars" INNER JOIN "car_colors" ON "car_colors"."car_id" = "cars"."id" WHERE "car_colors"."color_id" = 2 AND (created_at > '2013-05-03 12:28:36.551058') ORDER BY cars.created_at DESC
生成的SQL查询(在错误消息下面)似乎没有问题，但是什么导致了错误消息？
提前谢谢你.