CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3activerecord
Ramoji
Ramoji

Reputation: 110

Multiple joins with conditions in rails 3.2.7

I am stuck again with a simple query. I have the following models 

class Category < ActiveRecord::Base
  has_many :item_types
  has_many :items, :through => :item_types, :source => :category    
end

class ItemType < ActiveRecord::Base
  belongs_to :category
  has_many :items 
end

class Item
  belongs_to :item_type
end

Now I am trying to write a query that fetches all the items that fall under a category. I've written a query like this:

Category.joins(:item_types,:items).where("category.id=?",1)

Its throwing me an error when where condition is included. I have no clue why it does that.I thought this is a very basic join i could do it myself but in vain.

Upvotes: 0

Views: 620

Answers (3)

Rubyman
Rubyman

Reputation: 874

Category.joins(:item_types,:items).where("**categories**.id=?",1)

table name for category should be in where clause

Upvotes: 0

st8998
st8998

Reputation: 36

Category.joins(:item_types, :items).where(:item_type => {:category_id => 1})

Upvotes: 2

Nick Kugaevsky
Nick Kugaevsky

Reputation: 2945

It's much simpler if you want to build many-to-many association with ActiveRecord. If I clearly understand your question you should do something like this

# app/models/category.rb
class Category < ActiveRecord::Base
  has_many :item_types
  has_many :items, :through => :item_types
end

# app/models/item_type.rb
class ItemType < ActiveRecord::Base
  belongs_to :category
  belongs_to :item
end

# app/models/item.rb
class Item < ActiveRecord::Base
  has_many :item_types
  has_many :categories, :through => :item_types
end

# app/controllers/categories_controller.rb
def show
  @category = Category.find(params[:id])
  @category_items = @category.items
end

Upvotes: 0

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