相同型号的两个belongs_to协会

Question

我有一个型号PointOfContact其中has_manySystems。从Systems方面我想确定PointOfContact作为technical_manager或project_manager（或两者）。虽然仍然只在数据库中保留PointOfContact 1次。

我尝试如下：

class System < ActiveRecord::Base 
    belongs_to :project_manager, :class_name => 'PointOfContact' 
    belongs_to :technical_manager, :class_name => 'PointOfContact' 
end 

class PointOfContact < ActiveRecord::Base 
    has_many :systems 
end 

当我跑我的规格（例如如下）我可以正确地创建System点接触关联。但是，PointOfContact不知道它与系统的关联。这是为什么？

@sys = System.create 
@tm = PointOfContact.create 
@pm = PointOfContact.create 

@sys.project_manager = @pm 
@sys.technical_manager = @tm 

@pm.systems.should have(1).items #> expected 1 items, got 0 

Answer 1

由于在RailsForum.com jamesw过来：Same Model for Two belongs_to Associations的解决方案已被发现。

class System < ActiveRecord::Base 
    belongs_to :project_manager, :class_name => 'PointOfContact', :foreign_key => 'project_manager_id' 
    belongs_to :technical_manager, :class_name => 'PointOfContact', :foreign_key => 'technical_manager_id' 
end 

class PointOfContact < ActiveRecord::Base 
    has_many :project_managed_systems, :class_name => 'System', :foreign_key => 'project_manager_id' 
    has_many :technical_managed_systems, :class_name => 'System', :foreign_key => 'technical_manager_id' 
end