ActiveRecord忽略table_name_prefix [英] ActiveRecord ignores table_name_prefix

问题描述

我遇到这样的情况，我需要在模型中定义table_name和table_name_prefix，并且出于某种原因table_name会覆盖table_name_prefix。

I've got situation where I need to define table_name and table_name_prefix within a model and for some reason table_name overrides table_name_prefix.

class ScheduleItem < ActiveRecord::Base
  self.table_name = "schedule_item"
  self.table_name_prefix = 'ACQ_IBM_T.'
end

前缀在查询中被完全忽略。但是，当我注释掉table_name部分时，会添加前缀。

The prefix is completely ignored in the queries. But, when I comment out the table_name part then the prefix is added. Anyone has seen strange behavior like this before?

推荐答案

在 ActiveRecord :: ModelSchema :: ClassMethods ， table_name 设置器将值放在 @table_name ：

def table_name=(value)
  ...
  @table_name        = value

和 table_name getter仅使用 @table_name 值（如果已定义）：

And the table_name getter just uses the @table_name value if it is defined:

def table_name
  reset_table_name unless defined?(@table_name)
  @table_name
end

table_name_prefix 仅在试图根据类名猜测表名时用于帮助Rails（在 reset_table_name ）。

The table_name_prefix is only used to help Rails when it is trying to guess the table name based on the class name (in reset_table_name).

如果您拥有Rails不能猜测的表名，则可以执行以下操作：

If you have a table name that Rails can't guess, you can do this:

class ScheduleItem < ActiveRecord::Base
  self.table_name = "ACQ_IBM_T.schedule_item"

或者如果您需要要在其他地方使用前缀，您可以执行以下操作：

Or if you need to use the prefix somewhere else, you can do this:

class ScheduleItem < ActiveRecord::Base
  self.table_name_prefix = 'ACQ_IBM_T.'
  self.table_name = "#{table_name_prefix}schedule_item"

这篇关于ActiveRecord忽略table_name_prefix的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！