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    <p>the Item model could be declared as polymorphic (se here: <a href="http://guides.rails.info/association_basics.html#polymorphic-associations" rel="nofollow noreferrer">http://guides.rails.info/association_basics.html#polymorphic-associations</a>)</p> <p>so you'll declare Item:</p> <pre><code>class Item &lt; ActiveRecord::Base belongs_to :category, :polymorphic =&gt; true end </code></pre> <p>then the 3 models that act as category (I'll show one, the others are same):</p> <pre><code> class Employee &lt; ActiveRecord::Base has_one :item, :as =&gt; :category end # and so on... </code></pre> <p>this way you can associate an Item to one of the 3 models (Book, Furniture and Electronics). each instance of these models will have an 'items' atribute, like this:</p> <pre><code>@book.items # returns all the items associated to a @book object </code></pre> <p>You can also use has_many association using a polymorphic model.</p> <p>For the views, you can use Nested Form Objects (see here: <a href="http://guides.rails.info/form_helpers.html" rel="nofollow noreferrer">http://guides.rails.info/form_helpers.html</a>). basically, in each form, you should nest a form to create an Item object. to follow the Book example, you'll have something like this:</p> <pre><code> &lt;%= form_for :book, @book do |form| %&gt; &lt;%= form.text_field :isbn %&gt; &lt;!-- other fields --&gt; &lt;%= fields_for @book.item do |item_form| %&gt; &lt;%= item_form.text_field :name %&gt; &lt;% end %&gt; &lt;% end %&gt; </code></pre> <p>hope this helped you ;)</p>
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    1. POHow to Model Multiple Relationships in ActiveRecord?
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    1. USAndrea Pavoni
    1. USAndrea Pavoni
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    1. COApeacox, Thank you for your response. I watched a Ryan Bates video the other day, and I somewhat understood Polymorphic relations. His example of a comment being applicable to different models made sense. I had a feeling I might need to apply the polymorphic relation here as well. Please verify if this the best approach: BOOK,FURNITURE all belong to model CATEGORY, which belongs to ITEM, or ITEM has one category(BOOK,or FURNITURE). Do I need the model category at all? If i do I would assume that I would make the ITEM model a polymorphic one, that can belong to any one of 3 CATEGORIES. Right?
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    2. COyes, if you make Item polymorphic, it can belong to one of the 3 categories. you'll refer to them as 'category' (see the example in my answer). so an @item can do @item.category_id and @item.category_type to know the exact object (class and id of the model), then you can refer to @item.category.isbn if the category is a Book or @item.category.price if it's a Furniture
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      1. USAndrea Pavoni
 

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