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-rw-r--r--activerecord/lib/active_record/relation/calculations.rb16
1 files changed, 16 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index af86771d2d..bf9b4bf1c9 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -166,6 +166,22 @@ 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)
+ klass.connection.select_all(select(column_name).arel).map! do |attributes|
+ klass.type_cast_attribute(attributes.keys.first, klass.initialize_attributes(attributes))
+ end
+ end
+
private
def perform_calculation(operation, column_name, options = {})