如何在 rails 中获取 has_many 关系的通过关系的名称？

Question

我有：

class Foo
   has_many :bar
   has_many :baz, through :bar
end


class FooTwo
   has_many :barTwo
   has_many :baz, through :barTwo
end

我需要能够打通baz关联关系，比如：

Foo.first.baz.relation_through #<=> Foo.first.bar
FooTwo.first.baz.relation_through #<=> Foo.first.barTwo

如果不可能，我可以只得到名字吗？喜欢 :

Foo.first.baz.get_relation_through_name # "bar"
FooTwo.first.baz.get_relation_through_name # "barTwo"

Answer 1

您正在寻找这个：http://apidock.com/rails/ActiveRecord/Reflection/ClassMethods/reflect_on_all_associations

Foo.reflect_on_all_associations(:has_many) 

然后选择名字。

Answer 2

试试这个

Foo.reflect_on_all_associations.find { |association| association.name == :baz}.options[:through]