Postgresql with Hstore in Ruby on Rails 4 applications :)

We can use Nosql in Postgres :-), Excited right ? Yep Ruby on Rails 4 supports this via Hstore.

I had to query my Model tuples but it was not possible as i was using Serialize to store dynamic fields. But using Hstore we can easily achieve this like as follows , Hstore acts same as serialize in rails, but additionally we can query tables using Hstore.

 console
   p = Chocolate.last
   p.properties = {'color' => 'orange'}
   p.properties['price'] = '5'
   p.save
   Chocolate.where("color -> 'orange' ")
   Chocolate.where("price -> '5' ")

Follow steps below to enable Hstore in Rails 4 + Postgresql applications.

   rails generate migration enable_hstore_extension
   class EnableHstoreExtension < ActiveRecord::Migration
     def change
      enable_extension 'hstore'
     end
   end
   rake db:migrate



Now create a migration that will add a column called 'properties' to our Chocolate model.

  rails g migration AddPropertiesToChocolate

  class AddPropertiesToChocolate < ActiveRecord::Migration
    def change
      add_column :chocolates, :properties, :hstore
    end
  end
  
  rake db:migrate