From a382d60f6abc94b6a965525872f858e48abc00de Mon Sep 17 00:00:00 2001 From: Bogdan Gusiev Date: Wed, 30 Nov 2011 11:03:00 +0200 Subject: ActiveRecord::Relation#pluck method --- .../lib/active_record/associations/collection_proxy.rb | 2 +- activerecord/lib/active_record/base.rb | 2 +- activerecord/lib/active_record/relation/calculations.rb | 17 +++++++++++++++++ 3 files changed, 19 insertions(+), 2 deletions(-) (limited to 'activerecord/lib/active_record') diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb index 3181ca9a32..80bc4990d2 100644 --- a/activerecord/lib/active_record/associations/collection_proxy.rb +++ b/activerecord/lib/active_record/associations/collection_proxy.rb @@ -39,7 +39,7 @@ module ActiveRecord instance_methods.each { |m| undef_method m unless m.to_s =~ /^(?:nil\?|send|object_id|to_a)$|^__|^respond_to|proxy_/ } delegate :group, :order, :limit, :joins, :where, :preload, :eager_load, :includes, :from, - :lock, :readonly, :having, :to => :scoped + :lock, :readonly, :having, :pluck, :to => :scoped delegate :target, :load_target, :loaded?, :scoped, :to => :@association diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb index 484fe5fb16..2a02380591 100644 --- a/activerecord/lib/active_record/base.rb +++ b/activerecord/lib/active_record/base.rb @@ -449,7 +449,7 @@ module ActiveRecord #:nodoc: delegate :select, :group, :order, :except, :reorder, :limit, :offset, :joins, :where, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :create_with, :uniq, :to => :scoped - delegate :count, :average, :minimum, :maximum, :sum, :calculate, :to => :scoped + delegate :count, :average, :minimum, :maximum, :sum, :calculate, :pluck, :to => :scoped def inherited(child_class) #:nodoc: # force attribute methods to be higher in inheritance hierarchy than other generated methods diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index af86771d2d..0f57e9831d 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -166,6 +166,23 @@ module ActiveRecord 0 end + # This method is designed to perform select by a single column as direct SQL query + # Returns Array with values of the specified column name + # The values has same data type as column. + # + # Examples: + # + # Person.pluck(:id) # SELECT people.id FROM people + # Person.uniq.pluck(:role) # SELECT DISTINCT role FROM people + # Person.where(:confirmed => true).limit(5).pluck(:id) + # + def pluck(column_name) + scope = self.select(column_name) + self.connection.select_values(scope.to_sql).map! do |value| + type_cast_using_column(value, column_for(column_name)) + end + end + private def perform_calculation(operation, column_name, options = {}) -- cgit v1.2.3