This ActiverRecord plugin allows you to easily define and pull statistics for AR models. This plugin was built with reporting in mind.
script/plugin install git://github.com/acatighera/statistics.git
class Account < ActiveRecord::Base
define_statistic :user_count, :count => :all
define_statistic :average_age, :average => :all, :column_name => 'age'
define_statistic :subscriber_count, :count => :all, :conditions => "subscription_opt_in = 1"
end
class Donations < ActiveRecord::Base
define_statistic :total_donations, :sum => :all, :column_name => "amount"
end
#####for all stats
Account.statistics # returns { :user_count => 120, :average_age => 28, :subscriber_count => 74 }
#####for a single stat
Account.get_stat(‘:user_count’) # returns 120
Note: I found filtering to be an important part of reporting (ie. filtering by date). All filters are optional so even if you define them you don’t have to use them when pulling data. Using the filter_all_stats_on method and :joins options you can make things filterable by the same things which I found to be extremely useful.
class Account < ActiveRecord::Base
define_statistic :user_count, :count => :all, , :filter_on => { :state => 'state = ?', :created_after => 'DATE(created_at) > ?'}
define_statistic :subscriber_count, :count => :all, :conditions => "subscription_opt_in = true"
filter_all_stats_on(:account_type, "account_type = ?")
end
Account.statistics(:account_type => 'non-admin')
Account.get_stat(:user_count, :account_type => 'non-admin', :created_after => ‘2009-01-01’, :state => 'NY')
All ActiveRecord classes now respond to statistics and get_stat methods
all_stats = []
[ Account, Post, Comment ].each do |ar|
all_stats << ar.statistics
end
You can define calculated metrics in order to perform mathematical calculations on one or more defined statistics.
class Account < ActiveRecord::Base
has_many :donations
define_statistic :user_count, :count => :all
define_statistic :total_donations, :sum => :all, :column_name => 'donations.amount', :joins => :donations
define_calculated_statistic :average_donation_per_user do
defined_stats(:total_donations) / defined_stats(:user_count)
end
filter_all_stats_on(:account_type, "account_type = ?")
filter_all_stats_on(:state, "state = ?")
filter_all_stats_on(:created_after, "DATE(created_at) > ?")
end
Pulling stats for calculated metrics is the same as for regular statistics. They also work with filters like regular statistics!
Account.get_stat(:average_donation_per_user, :account_type => 'non-admin', :state => 'NY')
Account.get_stat(:average_donation_per_user, :created_after => '2009-01-01')
You can reuse the code you have written to do reporting.
class Account < ActiveRecord::Base
has_many :posts
named_scope :not_admins, :conditions => “account_type = ‘non-admin’”
named_scope :accounts_with_posts, :joins => :posts
define_statistic :active_users_count, :count => [:not_admins, :accounts_with_posts]
end
The :conditions and :joins options are all particularly useful
class Account < ActiveRecord::Base
has_many :posts
define_statistic :active_users_count, :count => :all, :joins => :posts, :conditions => "account_type = 'non-admin'"
end