diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/calculations.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index 9a7ff87e88..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 <tt>Array</tt> 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 = {}) @@ -223,7 +240,7 @@ module ActiveRecord query_builder = relation.arel end - type_cast_calculated_value(@klass.connection.select_value(query_builder.to_sql), column_for(column_name), operation) + type_cast_calculated_value(@klass.connection.select_value(query_builder), column_for(column_name), operation) end def execute_grouped_calculation(operation, column_name, distinct) #:nodoc: @@ -259,7 +276,7 @@ module ActiveRecord relation = except(:group).group(group.join(',')) relation.select_values = select_values - calculated_data = @klass.connection.select_all(relation.to_sql) + calculated_data = @klass.connection.select_all(relation) if association key_ids = calculated_data.collect { |row| row[group_aliases.first] } |