2 files changed, 5 insertions, 2 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb
index 6bf3050af9..50239f7cb2 100644
--- a/activerecord/lib/active_record/relation/calculations.rb
+++ b/activerecord/lib/active_record/relation/calculations.rb
@@ -177,6 +177,9 @@ module ActiveRecord
     #   Person.where(:confirmed => true).limit(5).pluck(:id)
     #
     def pluck(column_name)
+      if column_name.is_a?(Symbol) && column_names.include?(column_name.to_s)
+        column_name = "#{table_name}.#{column_name}"
+      end
       klass.connection.select_all(select(column_name).arel).map! do |attributes|
         klass.type_cast_attribute(attributes.keys.first, klass.initialize_attributes(attributes))
       end
diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb
index cc4ef2d078..87dd513880 100644
--- a/activerecord/lib/active_record/relation/query_methods.rb
+++ b/activerecord/lib/active_record/relation/query_methods.rb
@@ -201,7 +201,7 @@ module ActiveRecord
     #
     # The returned NullRelation inherits from Relation and implements the
     # Null Object pattern so it is an object with defined null behavior:
-    # it always returns an empty array of records and avoids any database query.
+    # it always returns an empty array of records and does not query the database.
     #
     # Any subsequent condition chained to the returned relation will continue
     # generating an empty relation and will not fire any query to the database.
@@ -212,7 +212,7 @@ module ActiveRecord
     # For example:
     #
     #   @posts = current_user.visible_posts.where(:name => params[:name])
-    #   # => the visible_post method response has to be a chainable Relation
+    #   # => the visible_posts method is expected to return a chainable Relation
     #
     #   def visible_posts
     #     case role