Mention `where.not` in the example

...so it doesn't look like you *have* to use SQL strings for that case (not
anymore!). Would like to replace the SQL string example with something that
you cannot do with the "normal" query API, but I could not come up with a
short, realistic example. Suggestions welcome!

activerecord/lib/active_record/enum.rb

@@ -36,6 +36,7 @@ module ActiveRecord
   # needs:
   #
   #   Conversation.where(status: [:active, :archived])
+  #   Conversation.where.not(status: :active)
   #
   # You can set the default value from the database declaration, like:
   #
@@ -69,9 +70,8 @@ module ActiveRecord
   #   Conversation.statuses[:active]    # => 0
   #   Conversation.statuses["archived"] # => 1
   #
-  # Use that class method when you need to know the ordinal value of an enum. For
-  # example, you can use that when manually building a SQL string inside a `where`
-  # condition:
+  # Use that class method when you need to know the ordinal value of an enum.
+  # For example, you can use that when manually building SQL strings:
   #
   #   Conversation.where("status <> ?", Conversation.statuses[:archived])
   #

activerecord/test/cases/enum_test.rb

@@ -42,6 +42,8 @@ class EnumTest < ActiveRecord::TestCase
     refute_equal @book, Book.where(status: :written).first
     assert_equal @book, Book.where(status: [:proposed]).first
     refute_equal @book, Book.where(status: [:written]).first
+    refute_equal @book, Book.where.not(status: :proposed).first
+    assert_equal @book, Book.where.not(status: :written).first
   end
 
   test "find via where with strings" do
@@ -49,6 +51,8 @@ class EnumTest < ActiveRecord::TestCase
     refute_equal @book, Book.where(status: "written").first
     assert_equal @book, Book.where(status: ["proposed"]).first
     refute_equal @book, Book.where(status: ["written"]).first
+    refute_equal @book, Book.where.not(status: "proposed").first
+    assert_equal @book, Book.where.not(status: "written").first
   end
 
   test "build from scope" do