Cassandra Object¶ ↑

Cassandra Object uses ActiveModel to mimic much of the behavior in ActiveRecord.

Installation¶ ↑

Add the following to your Gemfile:

gem 'cassandra', :require => '0.8'
gem 'jkusar-cassandra_object'

Change the version of Cassandra accordingly. Recent versions have not been backward compatible.

Defining Models¶ ↑

class Widget < CassandraObject::Base
  key :uuid
  string :name
  string :description
  integer :price
  array :colors, :unique => true

  validates :name, :presence => :true

  before_create do
    self.description = "#{name} is the best product ever"
  end
end

Connecting to the Server¶ ↑

CassandraObject::Base.establish_connection(
  :keyspace => 'my_app_development',
  :servers => '127.0.0.1:9160',
  :thrift => {
    :timeout => 20
    :retries => 2
  }
)

Creating and updating records¶ ↑

Cassandra Object has equivalent methods as ActiveRecord:

widget = Widget.new
widget.valid?
widget = Widget.create(:name => 'Acme', :price => 100)
widget.update_attribute(:price, 1200)
widget.update_attributes(:price => 1200, :name => 'Acme Corporation')
widget.attributes = {:price => 300}
widget.price_was
widget.save
widget.save!

Finding records¶ ↑

widget = Widget.find(uuid)
widget = Widget.first
widgets = Widget.all
Widget.find_each do |widget|
  ...
end

CQL is currently not supported