Question

The following works, properly, but seems like I m probably not utilizing something in rails that I should be. The working bit is:

MaxOffer.joins("JOIN items ON items.id = max_offers.item_id")
        .order( amount_in_cents desc )
        .where( items.id = 20 )
        .limit(5).collect do |moffer|

首先,我假定我没有必要明确使用加入书,因为模型是:

class MaxOffer < ActiveRecord::Base
  belongs_to :item
  belongs_to :user

class User < ActiveRecord::Base
  has_many :bids
  has_many :max_offers

But got errors when I tried to simply use item.id in the where clause. Is there a more proper way to do this, or is explicitly including the join necessary?

Answer 1

鉴于马克斯·乌弗赖斯与项目之间的关系,这项工作应当:

MaxOffer.joins(:item)
    .where( items.id = ? , 20)
    .order( amount_in_cents desc )
    .limit(5).collect do |moffer|

我把这两条放在了一边,看一下产生的q,看看看是否存在差异。

友情链接