New #update_columns method.

activerecord/lib/active_record/persistence.rb

@@ -229,6 +229,23 @@ def update_attributes!(attributes, options = {})
       end
     end
 
+    # Updates the attributes from the passed-in hash, without calling save.
+    #
+    # * Validation is skipped.
+    # * Callbacks are skipped.
+    # * updated_at/updated_on column is not updated if that column is available.
+    #
+    # Raises an +ActiveRecordError+ when called on new objects, or when at least
+    # one of the attributes is marked as readonly.
+    def update_columns(attributes)
+      raise ActiveRecordError, "can not update on a new record object" unless persisted?
+      attributes.each_key {|key| raise ActiveRecordError, "#{key.to_s} is marked as readonly" if self.class.readonly_attributes.include?(key.to_s) }
+      attributes.each do |k,v|
+        raw_write_attribute(k,v)
+      end
+      self.class.where(self.class.primary_key => id).update_all(attributes) == 1
+    end
+
     # Initializes +attribute+ to zero if +nil+ and adds the value passed as +by+ (default is 1).
     # The increment is performed directly on the underlying attribute, no setter is invoked.
     # Only makes sense for number-based attributes. Returns +self+.

activerecord/test/cases/persistence_test.rb

@@ -524,6 +524,63 @@ def test_update_column_with_one_changed_and_one_updated
     assert_equal 'super_title', t.title
   end
 
+  def test_update_columns
+    topic = Topic.find(1)
+    topic.update_columns({ "approved" => true, title: "Sebastian Topic" })
+    assert topic.approved?
+    assert_equal "Sebastian Topic", topic.title
+    topic.reload
+    assert topic.approved?
+    assert_equal "Sebastian Topic", topic.title
+  end
+
+  def test_update_columns_should_raise_exception_if_new_record
+    topic = Topic.new
+    assert_raises(ActiveRecord::ActiveRecordError) { topic.update_columns({ approved: false }) }
+  end
+
+  def test_update_columns_should_not_leave_the_object_dirty
+    topic = Topic.find(1)
+    topic.update_attributes({ "content" => "Have a nice day", :author_name => "Jose" })
+
+    topic.reload
+    topic.update_columns({ content: "You too", "author_name" => "Sebastian" })
+    assert_equal [], topic.changed
+
+    topic.reload
+    topic.update_columns({ content: "Have a nice day", author_name: "Jose" })
+    assert_equal [], topic.changed
+  end
+
+  def test_update_columns_with_one_readonly_attribute
+    minivan = Minivan.find('m1')
+    prev_color = minivan.color
+    prev_name = minivan.name
+    assert_raises(ActiveRecord::ActiveRecordError) { minivan.update_columns({ name: "My old minivan", color: 'black' }) }
+    assert_equal prev_color, minivan.color
+    assert_equal prev_name, minivan.name
+
+    minivan.reload
+    assert_equal prev_color, minivan.color
+    assert_equal prev_name, minivan.name
+  end
+
+  def test_update_columns_should_not_modify_updated_at
+    developer = Developer.find(1)
+    prev_month = Time.now.prev_month
+
+    developer.update_column(:updated_at, prev_month)
+    assert_equal prev_month, developer.updated_at
+
+    developer.update_columns({ salary: 80000 })
+    assert_equal prev_month, developer.updated_at
+    assert_equal 80000, developer.salary
+
+    developer.reload
+    assert_equal prev_month.to_i, developer.updated_at.to_i
+    assert_equal 80000, developer.salary
+  end
+
   def test_update_attributes
     topic = Topic.find(1)
     assert !topic.approved?

railties/guides/source/active_record_validations_callbacks.textile

@@ -86,6 +86,7 @@ The following methods skip validations, and will save the object to the database
 * +update_all+
 * +update_attribute+
 * +update_column+
+* +update_columns+
 * +update_counters+
 
 Note that +save+ also has the ability to skip validations if passed +:validate => false+ as argument. This technique should be used with caution.
@@ -1056,6 +1057,7 @@ Just as with validations, it is also possible to skip callbacks. These methods s
 * +toggle+
 * +touch+
 * +update_column+
+* +update_columns+
 * +update_all+
 * +update_counters+