require File.dirname(__FILE__) + '/shared_setup' logger = Logger.new(STDOUT) # Database setup --------------- logger.info "\nCreate tables" [ "DROP TABLE companies", "DROP TABLE people", "DROP TABLE people_companies", "CREATE TABLE companies (id int(11) auto_increment, client_of int(11), name varchar(255), type varchar(100), PRIMARY KEY (id))", "CREATE TABLE people (id int(11) auto_increment, name varchar(100), PRIMARY KEY (id))", "CREATE TABLE people_companies (person_id int(11), company_id int(11), PRIMARY KEY (person_id, company_id))", ].each { |statement| # Tables doesn't necessarily already exist begin; ActiveRecord::Base.connection.execute(statement); rescue ActiveRecord::StatementInvalid; end } # Class setup --------------- class Company < ActiveRecord::Base has_and_belongs_to_many :people, :class_name => "Person", :join_table => "people_companies", :table_name => "people" end class Firm < Company has_many :clients, :foreign_key => "client_of" def people_with_all_clients clients.inject([]) { |people, client| people + client.people } end end class Client < Company belongs_to :firm, :foreign_key => "client_of" end class Person < ActiveRecord::Base has_and_belongs_to_many :companies, :join_table => "people_companies" def self.table_name() "people" end end # Usage --------------- logger.info "\nCreate fixtures" Firm.new("name" => "Next Angle").save Client.new("name" => "37signals", "client_of" => 1).save Person.new("name" => "David").save logger.info "\nUsing Finders" next_angle = Company.find(1) next_angle = Firm.find(1) next_angle = Company.find_first "name = 'Next Angle'" next_angle = Firm.find_by_sql("SELECT * FROM companies WHERE id = 1").first Firm === next_angle logger.info "\nUsing has_many association" next_angle.has_clients? next_angle.clients_count all_clients = next_angle.clients thirty_seven_signals = next_angle.find_in_clients(2) logger.info "\nUsing belongs_to association" thirty_seven_signals.has_firm? thirty_seven_signals.firm?(next_angle) logger.info "\nUsing has_and_belongs_to_many association" david = Person.find(1) david.add_companies(thirty_seven_signals, next_angle) david.companies.include?(next_angle) david.companies_count == 2 david.remove_companies(next_angle) david.companies_count == 1 thirty_seven_signals.people.include?(david)