If I have a Invitation model and a User model, with the Invitation model having a requester_id column, why does this work,
如果我有一个邀请模型和一个用户模型，邀请模型有一个requester_id列，为什么这样做，
class Invitation < ActiveRecord::Base
belongs_to :requester, :class_name => "User"
end
and this doesn't work?
这不起作用？
class Invitation < ActiveRecord::Base
belongs_to :requester, :class_name => :user
end
In general, when do I use symbols, and when do I use strings in Rails 3?
一般来说，我何时使用符号，何时在Rails 3中使用字符串？
2 个解决方案
#1
2
Either One
You would certainly need :User, not :user.
你当然需要：用户，而不是：用户。
The core Ruby Symbol defines a #to_s and String defines a #to_sym, so in any Ruby context you may often substitute one for another.
核心Ruby符号定义了#to_s，String定义了#to_sym，因此在任何Ruby上下文中，您可能经常将一个替换为另一个。
I might be tempted to say: when in doubt, follow the Rails3 API documentation. except it doesn't say, although the example uses a string. But in this case, it works, you can safely use a symbol.
我可能会说：如有疑问，请遵循Rails3 API文档。除了它没有说，虽然该例子使用了一个字符串。但在这种情况下，它可以工作，你可以安全地使用符号。
#2
0
Remember that it is case sensitive. So :User may work. In any case, I would use a string as that's what it says in the docs :)
请记住，它区分大小写。所以：用户可以工作。在任何情况下，我会使用一个字符串，因为它是在文档中说的:)
#1
2
Either One
You would certainly need :User, not :user.
你当然需要：用户，而不是：用户。
The core Ruby Symbol defines a #to_s and String defines a #to_sym, so in any Ruby context you may often substitute one for another.
核心Ruby符号定义了#to_s，String定义了#to_sym，因此在任何Ruby上下文中，您可能经常将一个替换为另一个。
I might be tempted to say: when in doubt, follow the Rails3 API documentation. except it doesn't say, although the example uses a string. But in this case, it works, you can safely use a symbol.
我可能会说：如有疑问，请遵循Rails3 API文档。除了它没有说，虽然该例子使用了一个字符串。但在这种情况下，它可以工作，你可以安全地使用符号。
#2
0
Remember that it is case sensitive. So :User may work. In any case, I would use a string as that's what it says in the docs :)
请记住，它区分大小写。所以：用户可以工作。在任何情况下，我会使用一个字符串，因为它是在文档中说的:)