Merged pull request #302 from metaskills/empty_inserts.

Use existing #empty_insert_statement_value for an insert with no columns.

activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb

@@ -287,10 +287,6 @@ module ActiveRecord
         execute "INSERT INTO #{quote_table_name(table_name)} (#{key_list.join(', ')}) VALUES (#{value_list.join(', ')})", 'Fixture Insert'
       end
 
-      def null_insert_value
-        Arel.sql 'DEFAULT'
-      end
-
       def empty_insert_statement_value
         "VALUES(DEFAULT)"
       end

activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb

@@ -346,10 +346,6 @@ module ActiveRecord
         alter_table(table_name, :rename => {column_name.to_s => new_column_name.to_s})
       end
 
-      def null_insert_value
-        Arel.sql 'NULL'
-      end
-
       def empty_insert_statement_value
         "VALUES(NULL)"
       end

activerecord/lib/active_record/relation.rb

@@ -60,7 +60,7 @@ module ActiveRecord
       end
 
       if values.empty? # empty insert
-        im.values = im.create_values [connection.null_insert_value], []
+        im.values = Arel.sql(connection.empty_insert_statement_value)
       else
         im.insert substitutes
       end