Merge pull request rails#43437 from ashiksp/updated-disable-joins-examples

Updated disable_joins examples for has_one through association.

Author: eileencodes

activerecord/CHANGELOG.md

@@ -647,7 +647,7 @@
 
     ```ruby
     class Person
-      belongs_to :dog
+      has_one :dog
       has_one :veterinarian, through: :dog, disable_joins: true
     end
     ```

guides/source/active_record_multiple_databases.md

@@ -506,9 +506,18 @@ class Dog < AnimalsRecord
   has_many :treats, through: :humans, disable_joins: true
   has_many :humans
 
-  belongs_to :home
+  has_one :home
   has_one :yard, through: :home, disable_joins: true
 end
+
+class Home
+  belongs_to :dog
+  has_one :yard
+end
+
+class Yard
+  belongs_to :home
+end
 ```
 
 Previously calling `@dog.treats` without `disable_joins` or `@dog.yard` without `disable_joins`