Rails-连接多个表 [英] Rails - Joining multiple tables

问题描述

我有以下模型：

class Company < ActiveRecord::Base
  has_many :price_movements
  has_many :goods_movements
end

class PriceMovement < ActiveRecord::Base
  belongs_to :company
end

class GoodsMovement < ActiveRecord::Base
   belongs_to :company
end

我正在尝试加入一切都以activerecord的形式组合到一个sql中，但是我不确定该怎么做，因为我对ROR相对较新。

I am trying to join everything together into an sql in the form of activerecord, but I'm not sure how to go about doing it because I'm relatively new to ROR.

select * from companies c

inner join price_movements p
on c.id = p.company_id

inner join goods_movements g
on c.id = g.company_id
and g.date = p.date

我的主要问题是第二个链接，其中goods_movement date == price_movement日期。
有人可以建议是否有任何方法吗？

The key problem for me is the second link where goods_movement date == price_movement date. Can someone advice on whether there's any way to do it?

推荐答案

Company.joins(:price_movements,:goods_movements).where("goods_movement.date = price_movement.date")

通过此链接，其中详细说明了如何使用 ActiveRecord

Go through this link it has detailed explanation of how to use ActiveRecord

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