与自定义表名称关联的joins（）和where（）请求 [英] joins() and where() request on association with custom table name

问题描述

我有两个模型

Album.rb

class Album < ActiveRecord::Base
  has_many :tracks
  self.table_name = 'prefix_album'
end

Track.rb

class Track < ActiveRecord::Base
  belongs_to :album
  self.table_name = 'prefix_track'
end

现在，由于原因，表名带有前缀，所以我有 prefix_album 和 prefix_track 表在我的数据库中。对于基本用途，它可以正常工作。

Now, because reasons, the table names are prefixed, so I have prefix_album and prefix_track tables in my database. For basic use, it works fine.

现在出现以下查询问题：

Now the problem with the following query :

Album.joins(:tracks).where(tracks: { id: [10, 15] })

结果为以下SQL：

SELECT * FROM "prefix_albums" INNER JOIN "prefix_tracks" ON "prefix_tracks"."album_id" = "prefix_albums"."id" WHERE "tracks"."id" IN (10, 15)

哪个失败因为 WHERE tracks。 id 应该为 WHERE prefix_tracks。 id 。知道为什么active_record能够为 .joins（：tracks）而不为 .where（tracks {{}）？

Which fails because WHERE "tracks"."id" should be WHERE "prefix_tracks"."id". Any idea why active_record is able to get the correct table name for .joins(:tracks) but not for .where(tracks: {}) ?

无论如何我都想过这个练习： Album.joins（：tracks）.merge（Track.where（id ：[10,15]））给出相同的结果并起作用。

Anyway I have figured this workout : Album.joins(:tracks).merge(Track.where(id: [10,15])) which gives the same result and works.

但是我想知道为什么前者没有工作

But I would like to know why the former didn't work

推荐答案

尝试一下：

Album.joins(:tracks).where(prefix_tracks: { id: [10, 15] })

您可以将 table_name 添加到模型中，例如：

You can add table_name to the model like :

class Album < ActiveRecord::Base
  self.table_name = "prefix_album"
end

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