Add support for :primary_key option to has_one as well as has_many so that a key other than the default primary key can be used for the association

Signed-off-by: Michael Koziarski <michael@koziarski.com>

2 files changed, 12 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index c5e8207f14..856d872bce 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -759,6 +759,7 @@ module ActiveRecord
       # * <tt>:foreign_key</tt> - Specify the foreign key used for the association. By default this is guessed to be the name
       #   of this class in lower-case and "_id" suffixed. So a Person class that makes a +has_one+ association will use "person_id"
       #   as the default <tt>:foreign_key</tt>.
+      # * <tt>:primary_key</tt> - Specify the method that returns the primary key used for the association. By default this is +id+.
       # * <tt>:include</tt> - Specify second-order associations that should be eager loaded when this object is loaded.
       # * <tt>:as</tt> - Specifies a polymorphic interface (See <tt>belongs_to</tt>).
       # * <tt>:select</tt> - By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if, for example, you want to do a join
@@ -1366,7 +1367,7 @@ module ActiveRecord
 
         def create_has_one_reflection(association_id, options)
           options.assert_valid_keys(
-            :class_name, :foreign_key, :remote, :select, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :readonly, :validate
+            :class_name, :foreign_key, :remote, :select, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :readonly, :validate, :primary_key
           )
 
           create_reflection(:has_one, association_id, options, self)
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index 25a268e95c..fdc0fa52c9 100755
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -47,7 +47,16 @@ module ActiveRecord
           return (obj.nil? ? nil : self)
         end
       end
-            
+
+      protected
+        def owner_quoted_id
+          if @reflection.options[:primary_key]
+            quote_value(@owner.send(@reflection.options[:primary_key]))
+          else
+            @owner.quoted_id
+          end
+        end
+
       private
         def find_target
           @reflection.klass.find(:first,