Question

ActiveRecord::StatementInvalid: 
Mysql::Error: Unknown column 'schedules.id' in 'on clause': 
SELECT `schedules`.* FROM `schedules`   INNER JOIN `shops` ON 
(`schedules`.`id` = `shops`.`shop_id`)  INNER JOIN `areas` ON 
(`areas`.`id` = `shops`.`area_id`)

正确的sql语句应该包含'schedule'.'shop_id'='shops'。'id'而不是'schedules'。'id'='shops'。'shop_id'。为了实现这一目标，我可以在模型中做些什么改变？

以下是这三个类的模型：

class Area < ActiveRecord::Base  
  has_many :shops  
  has_many :schedules, :through => :shop  
end  

class Schedule < ActiveRecord::Base  
  belongs_to :shop  
  has_many :areas, :through => :shop  
end  

class Shop < ActiveRecord::Base  
  belongs_to :area # foreign key - area_id  
  has_many :schedule  
end

创建该sql命令的命令： Schedule.find：all，：joins =＆gt; [：shop，：areas]

在db / schema.rb中我有：

create_table "areas", :force => true do |t| 
  t.string   "campus"
  t.datetime "created_at"
  t.datetime "updated_at"
end 

create_table "shops", :force => true do |t|
  t.integer  "area_id"
  t.datetime "created_at"
  t.datetime "updated_at"
end

create_table "schedules", :force => true do |t|
  t.integer  "shop_id"
  t.datetime "created_at"
  t.datetime "updated_at"
end

Answer 1

我认为你的查询应该使用：include选项来指定

Schedule.find :all, :include => [:shops, :areas]

：join选项用于指定连接逻辑，例如“INNER JOIN ...”

Activerecord加入has_many：through

1 个答案: