[ci skip] Add Tip for change_column_null and change_column_default in…

… guides
rails · Jun 20, 2014 · 876908d · 876908d
1 parent 042f185
commit 876908d
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/guides/source/active_record_migrations.md b/guides/source/active_record_migrations.md
@@ -434,6 +434,8 @@ change_column_default :products, :approved, false
 This sets `:name` field on products to a `NOT NULL` column and the default
 value of the `:approved` field to false.
 
+TIP: Unlike `change_column` (and `change_column_default`), `change_column_null` is reversible.
+
 ### Column Modifiers
 
 Column modifiers can be applied when creating or changing a column: