# Derived model associates with a model that base associates with in a different way **URL:** \ **Category:** Rails\ **Created:** [May 24, 2010, 4:18am UTC](https://www.ruby-forum.com/t/derived-model-associates-with-a-model-that-base-associates-with-in-a-different-way/189076 "2010-05-24T04:18:48Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![ali](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/8c91f0/32.png) [@ali](https://www.ruby-forum.com/u/ali)\ **Post date:** [May 24, 2010, 4:18am UTC](https://www.ruby-forum.com/t/derived-model-associates-with-a-model-that-base-associates-with-in-a-different-way/189076/1 "2010-05-24T04:18:48Z")
Hello, So I have an Attribute model with lists the attributes of an object. The attributes can be of different types so I have derived classes as well, in this case I have a derived SubjectiveAttribute. The problem I’m having revolves around my User model. A user is allowed to give each attribute a weighting (which tells the system how important an attribute is to a user). So, there’s a Weight model and then Attribute has the associations has\_many :weights and has\_many :users, :through =\> :weights. The problem is that SubjectiveAttribute is related to the users in a different way, subjective attributes can be rated as well as weighted. So SubjectiveAttribute has the association has\_many :ratings and has\_many :users, :through =\> :ratings. def Attribute belongs\_to :attributable, :polymorphic =\> true has\_many :weights has\_many :users, :through =\> :weights def SubjectiveAttribute \< Attribtue has\_one :attribute, :as =\> :attributable has\_many :ratings has\_many :users, :through =\> :ratings Is this ok or are there problems which could occur that I’m no seeing? Are there going to be clashes or confusion when I do something like sub\_attribute.users or attribute.users? Thanks in advance.