使用自定义has_many关系时nil的未定义方法名称 [英] Undefined method name for nil when using custom has_many relationship

问题描述

我正在尝试为我的一个模型创建最简单的 has_many 关系。定义如下：

I'm trying to create the simplest has_many relationship possible for one of my models. It's defined like that:

# i know it doesn't make much sense. I'm using such ridiculous 
# where case to keep things simple for now
has_many :jobs, -> { where(id: 1) }, class_name: SidekiqJob

但是，当我尝试调用它时无论如何，例如与 MyModel.last.jobs 的关系，都会抛出异常：

However, when i' trying to call that relationship in anyway, for example with MyModel.last.jobs, rails throws:

NoMethodError: undefined method `name' for nil:NilClass
from /Volumes/HDD/Users/michal/.rvm/gems/ruby-2.1.1/gems/activerecord-4.0.3/lib/active_record/relation/merger.rb:141:in `block in filter_binds'

有人对它有任何想法

• 红宝石2.1.1


• 轨道4.0.3

• ruby 2.1.1
• rails 4.0.3

原始关联定义：

has_many :jobs, (obj) -> { where('jid LIKE ?', "#{obj.superjob_id}%") }, class_name: SidekiqJob

推荐答案

原来与ruby / active_record版本有关。根据此线程：通过关联使用has_many创建获取NoMethodError（nil：NilClass的未定义方法名称）

It turned out to be related to ruby/active_record versions. According to this thread: create with has_many through association gets NoMethodError (undefined method `name' for nil:NilClass)

我为修复红宝石版本所做的操作为 2.1.10 。然后，我摆脱了此类错误（因为它们被扔到了更多地方）。无论如何，我仍然无法 includes 我的关系。似乎不可能使用自定义where语句包括关系。

What i've done to "fix" that was to change my ruby version to 2.1.10. Then, i got rid of such errors (cause they've been thrown in more places). Anyway, i am still not able to includes my relation defined as in the OP. It seems that it's not possible to includes relations using custom where statements.

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