Rails 属于关联，当集合的一部分时无法访问所有者的属性？
我有一个物体，球，它属于一个女孩，它可以有很多球。大多数情况下一切正常，但如果我尝试通过以下方式打印出女孩的名字：
@balls.each do |b|
b.girl.name
end
我收到以下错误：
"undefined method `name' for nil:NilClass"
这真的让我很困惑。如果我说 b.girl.class，我会把它作为 Girl 的一个实例，很好。也就是说，它不是“NillClass”。
不仅如此，如果我对任何球尝试一下，并说
@ball.girl.name
我完全没问题。
到底是什么让我搞砸了《球》的收藏呢？
编辑：
具体来说，在我看来这正在发生。我现在正在进行测试，看看它是否也发生在控制器中。
I have an Object, Ball, which belongs_to a Girl, which can have_many balls. Everything works for the most part, but if I try to print out the girls' name via:
@balls.each do |b|
b.girl.name
end
I get the following error:
"undefined method `name' for nil:NilClass"
Which really confuses me. If I say b.girl.class, I get it as an instance of Girl, just fine. That is, it isn't "NillClass".
Not only that, if I just try it for any Ball, and say
@ball.girl.name
I'm perfectly fine.
What is it about a collection of Balls that is screwing me up?
Edit:
Specifically this is happening in my view. I'm doing testing now to see if it happens in the controller, too.
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评论（2）
您有一个
Ball实例，但没有关联的Girl。在访问girl的name属性之前，您需要检查以确保girl不为nil。You have an instance of
Ballwhich does not have an associatedGirl. You'll want to check to make sure thatgirlisn'tnilprior to accessing hernameattribute.丹吉特，好吧，没关系。问题是，由于某种原因，某些球对象实际上没有女孩（尽管大多数都有，所以我尝试的任何给定球都工作得很好，但如果我尝试做所有这些，其中一个会失败，并且视图错误只让我知道出了问题，而不是哪里出了问题）
Dangit, okay, never mind. The issue was that for some reason some Ball Object didn't actually have girls (though most did, so any given Ball I tried worked fine, but if I tried to do all of them, one of them would fail, and the view error only let me know that something went wrong, not where)