ActiveRecord::Relation#primary_key should return a string, just like ActiveRecord::Base.primary_key does.

1 files changed, 6 insertions, 13 deletions

diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 20e983b5f7..1441e9750e 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -10,7 +10,9 @@ module ActiveRecord
 
     include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches
 
+    # These are explicitly delegated to improve performance (avoids method_missing)
     delegate :to_xml, :to_yaml, :length, :collect, :map, :each, :all?, :include?, :to => :to_a
+    delegate :table_name, :primary_key, :to => :klass
 
     attr_reader :table, :klass, :loaded
     attr_accessor :extensions
@@ -30,13 +32,12 @@ module ActiveRecord
     def insert(values)
       im = arel.compile_insert values
       im.into @table
-      primary_key_name = @klass.primary_key
-      primary_key_value = primary_key_name && Hash === values ? values[primary_key] : nil
+      primary_key_value = primary_key && Hash === values ? values[table[primary_key]] : nil
 
       @klass.connection.insert(
         im.to_sql,
         'SQL',
-        primary_key_name,
+        primary_key,
         primary_key_value)
     end
 
@@ -177,7 +178,7 @@ module ActiveRecord
         stmt = arel.compile_update(Arel.sql(@klass.send(:sanitize_sql_for_assignment, updates)))
         stmt.take limit
         stmt.order(*order)
-        stmt.key = @klass.arel_table[@klass.primary_key]
+        stmt.key = table[primary_key]
         @klass.connection.update stmt.to_sql
       end
     end
@@ -320,7 +321,7 @@ module ActiveRecord
     #   # Delete multiple rows
     #   Todo.delete([2,3,4])
     def delete(id_or_array)
-      where(@klass.primary_key => id_or_array).delete_all
+      where(primary_key => id_or_array).delete_all
     end
 
     def reload
@@ -336,10 +337,6 @@ module ActiveRecord
       self
     end
 
-    def primary_key
-      @primary_key ||= table[@klass.primary_key]
-    end
-
     def to_sql
       @to_sql ||= arel.to_sql
     end
@@ -373,10 +370,6 @@ module ActiveRecord
       to_a.inspect
     end
 
-    def table_name
-      @klass.table_name
-    end
-
     protected
 
     def method_missing(method, *args, &block)