Added :select option to has_one and belongs_to, remove unused :order option on belongs_to.

Signed-off-by: Michael Koziarski <michael@koziarski.com>
[#241 state:resolved]

activerecord/lib/active_record/associations.rb

@@ -667,7 +667,7 @@ module ActiveRecord
       # * <tt>:limit</tt> - An integer determining the limit on the number of rows that should be returned.
       # * <tt>:offset</tt> - An integer determining the offset from where the rows should be fetched. So at 5, it would skip the first 4 rows.
       # * <tt>:select</tt> - By default, this is <tt>*</tt> as in <tt>SELECT * FROM</tt>, but can be changed if you, for example, want to do a join
-      #   but not include the joined columns.
+      #   but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will rise an error.
       # * <tt>:as</tt> - Specifies a polymorphic interface (See <tt>belongs_to</tt>).
       # * <tt>:through</tt> - Specifies a Join Model through which to perform the query.  Options for <tt>:class_name</tt> and <tt>:foreign_key</tt>
       #   are ignored, as the association uses the source reflection. You can only use a <tt>:through</tt> query through a <tt>belongs_to</tt>
@@ -747,6 +747,8 @@ module ActiveRecord
       #   as the default <tt>:foreign_key</tt>.
       # * <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
+      #   but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will raise an error.
       # * <tt>:through</tt>: Specifies a Join Model through which to perform the query.  Options for <tt>:class_name</tt> and <tt>:foreign_key</tt>
       #   are ignored, as the association uses the source reflection. You can only use a <tt>:through</tt> query through a 
       #   <tt>has_one</tt> or <tt>belongs_to</tt> association on the join model.
@@ -821,8 +823,8 @@ module ActiveRecord
       #   if the real class name is Person, you'll have to specify it with this option.
       # * <tt>:conditions</tt> - Specify the conditions that the associated object must meet in order to be included as a +WHERE+
       #   SQL fragment, such as <tt>authorized = 1</tt>.
-      # * <tt>:order</tt> - Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment,
+      # * <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
-      #   such as <tt>last_name, first_name DESC</tt>.
+      #   but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will raise an error.
       # * <tt>:foreign_key</tt> - Specify the foreign key used for the association. By default this is guessed to be the name
       #   of the association with an "_id" suffix. So a class that defines a <tt>belongs_to :person</tt> association will use
       #   "person_id" as the default <tt>:foreign_key</tt>. Similarly, <tt>belongs_to :favorite_person, :class_name => "Person"</tt>
@@ -1011,7 +1013,7 @@ module ActiveRecord
       # * <tt>:limit</tt> - An integer determining the limit on the number of rows that should be returned.
       # * <tt>:offset</tt> - An integer determining the offset from where the rows should be fetched. So at 5, it would skip the first 4 rows.
       # * <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
-      #   but not include the joined columns.
+      #   but not include the joined columns. Do not forget to include the primary and foreign keys, otherwise it will raise an error.
       # * <tt>:readonly</tt> - If true, all the associated objects are readonly through the association.
       #
       # Option examples:
@@ -1341,7 +1343,7 @@ module ActiveRecord
 
         def create_has_one_reflection(association_id, options)
           options.assert_valid_keys(
-            :class_name, :foreign_key, :remote, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :readonly
+            :class_name, :foreign_key, :remote, :select, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :readonly
           )
 
           create_reflection(:has_one, association_id, options, self)
@@ -1349,14 +1351,14 @@ module ActiveRecord
         
         def create_has_one_through_reflection(association_id, options)
           options.assert_valid_keys(
-            :class_name, :foreign_key, :remote, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :through, :source, :source_type
+            :class_name, :foreign_key, :remote, :select, :conditions, :order, :include, :dependent, :counter_cache, :extend, :as, :through, :source, :source_type
           )
           create_reflection(:has_one, association_id, options, self)
         end
 
         def create_belongs_to_reflection(association_id, options)
           options.assert_valid_keys(
-            :class_name, :foreign_key, :foreign_type, :remote, :conditions, :order, :include, :dependent,
+            :class_name, :foreign_key, :foreign_type, :remote, :select, :conditions, :include, :dependent,
             :counter_cache, :extend, :polymorphic, :readonly
           )
 

activerecord/lib/active_record/associations/belongs_to_association.rb

@@ -42,10 +42,11 @@ module ActiveRecord
       private
         def find_target
           @reflection.klass.find(
-            @owner[@reflection.primary_key_name], 
+            @owner[@reflection.primary_key_name],
+            :select     => @reflection.options[:select],
             :conditions => conditions,
             :include    => @reflection.options[:include],
-            :readonly => @reflection.options[:readonly]
+            :readonly   => @reflection.options[:readonly]
           )
         end
 

activerecord/lib/active_record/associations/belongs_to_polymorphic_association.rb

@@ -29,12 +29,13 @@ module ActiveRecord
 
           if @reflection.options[:conditions]
             association_class.find(
-              @owner[@reflection.primary_key_name], 
+              @owner[@reflection.primary_key_name],
+              :select     => @reflection.options[:select],
               :conditions => conditions,
               :include    => @reflection.options[:include]
             )
           else
-            association_class.find(@owner[@reflection.primary_key_name], :include => @reflection.options[:include])
+            association_class.find(@owner[@reflection.primary_key_name], :select => @reflection.options[:select], :include => @reflection.options[:include])
           end
         end
 

activerecord/lib/active_record/associations/has_one_association.rb

@@ -51,10 +51,11 @@ module ActiveRecord
       private
         def find_target
           @reflection.klass.find(:first, 
-            :conditions => @finder_sql, 
+            :conditions => @finder_sql,
+            :select     => @reflection.options[:select],
             :order      => @reflection.options[:order], 
             :include    => @reflection.options[:include],
-            :readonly    => @reflection.options[:readonly]
+            :readonly   => @reflection.options[:readonly]
           )
         end
 

activerecord/test/cases/associations/belongs_to_associations_test.rb

@@ -92,6 +92,11 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_not_nil Company.find(3).firm_with_condition, "Microsoft should have a firm"
   end
 
+  def test_with_select
+    assert_equal Company.find(2).firm_with_select.attributes.size, 1
+    assert_equal Company.find(2, :include => :firm_with_select ).firm_with_select.attributes.size, 1
+  end
+
   def test_belongs_to_counter
     debate = Topic.create("title" => "debate")
     assert_equal 0, debate.send(:read_attribute, "replies_count"), "No replies yet"

activerecord/test/cases/associations/has_one_associations_test.rb

@@ -24,6 +24,11 @@ class HasOneAssociationsTest < ActiveRecord::TestCase
     assert_queries(0) { firms.each(&:account) }
   end
 
+  def test_with_select
+    assert_equal Firm.find(1).account_with_select.attributes.size, 2
+    assert_equal Firm.find(1, :include => :account_with_select).attributes.size, 2
+  end
+
   def test_can_marshal_has_one_association_with_nil_target
     firm = Firm.new
     assert_nothing_raised do

activerecord/test/models/company.rb

@@ -47,6 +47,7 @@ class Firm < Company
   has_many :readonly_clients, :class_name => 'Client', :readonly => true
 
   has_one :account, :foreign_key => "firm_id", :dependent => :destroy
+  has_one :account_with_select, :foreign_key => "firm_id", :select => "id, firm_id"
   has_one :readonly_account, :foreign_key => "firm_id", :class_name => "Account", :readonly => true
 end
 
@@ -64,6 +65,7 @@ end
 class Client < Company
   belongs_to :firm, :foreign_key => "client_of"
   belongs_to :firm_with_basic_id, :class_name => "Firm", :foreign_key => "firm_id"
+  belongs_to :firm_with_select, :class_name => "Firm", :foreign_key => "firm_id", :select => "id"
   belongs_to :firm_with_other_name, :class_name => "Firm", :foreign_key => "client_of"
   belongs_to :firm_with_condition, :class_name => "Firm", :foreign_key => "client_of", :conditions => ["1 = ?", 1]
   belongs_to :readonly_firm, :class_name => "Firm", :foreign_key => "firm_id", :readonly => true