使用 has_many:through 进行 rails 关联急切加载

Question

I have trouble finding a way to link to class A to E. Here are the class implied:

A has many B
B belongs to A
B belongs to C
A has many C through B

C has many D
D belongs to C
D belongs to E class_name C
C has_many E through D

Ok I know it is confusing so I made a schema and I hope it is more comprehensible...

My question is how can I link the class A with the class E (that is in reality class C with a particula role). How can I use a.es (es => plural of E:s )?

I tried A has_many E through C (in my mind it was a good solution because A has_many C (through B) and C has_many E (through D)) but it raise an error:

ActiveRecord::HasManyThroughSourceAssociationMacroError: Invalid source reflection macro:has_many:through for has_many:es, :through =>:cs. Use:source to specify the source reflection

I'm coding on rails V2.3.9

If you have any idea please tell me. Thank you in advance.

Answer 1

Although there are some plugins that extend the :through relationship functionality, it's not generally possible to use ActiveRecord to navigate through multiple layers at the same time. The limit is generally one :through , no more.