Question

您好我的查询有问题。我的模型如下：

class Owner
  has_many :busiensses
  has_many :adverts
end

class Business
  belongs_to :owner
end

class Advert
  belongs_to :owner
end

当我进行此查询时，一切正常，并返回正确的集合，其中包含所需的对象：

 Owner.joins(:adverts).includes(:businesses)
   .where(businesses: {owner_id: nil})

但是当我添加到查询更新时会引发错误

 Owner.joins(:adverts).includes(:businesses)
   .where(businesses: {owner_id: nil})
   .update_all(status: 'sth')

错误：

 ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR:  missing FROM-clause entry for table "businesses"

问题出在哪里？我打赌这个错误来自SQL，当你忘记将 sth 添加到 FROM 语句并且在其他条件下需要 sth 时，它会引发错误我忘了添加它？

Answer 1

Owner.joins(:adverts)
 .includes(:businesses)
 .where(businesses: {owner_id: 1})
 .update_all(name: "blaaaaa")

此声明转换为此查询：

UPDATE "owners" 
SET "name" = 'blaaaaa' 
FROM "businesses" /* missed this */
WHERE "owners"."id" IN 
 (SELECT "owners"."id" FROM "owners" 
 INNER JOIN "adverts" 
 ON "adverts"."owner_id" = "owners"."id" 
 WHERE "businesses"."owner_id" = 1)

您错过导致错误的"FROM 'bussinesses'"：

表“business”缺少FROM子句条目

我的解决方案是使用joins而不是includes。它在我的机器上工作正常。

Owner.joins(:adverts)
 .joins(:businesses)
 .where(businesses: {owner_id: 1})
 .update_all(name: "blaaaaa")

=> 1

当有连接并包含在查询中时，Active Record不会更新集合

1 个答案: