Ticket #2479: aggregate.diff

db/models/query.py

@@ -301 +301 @@
         self._result_cache = None
     delete.alters_data = True
 
+    def aggregrate(self, function, field):
+        """Performs a simple aggregate function on field"""
+        counter = self._clone()
+        counter._order_by = ()
+        counter._offset = None
+        counter._limit = None
+        counter._select_related = False
+        select, sql, params = counter._get_sql_clause()
+        cursor = connection.cursor()
+        # absolutely no input checking
+        cursor.execute( "SELECT %s(%s)" % (function, backend.quote_name(field)) + sql, params)
+        return cursor.fetchone()[0]        
+
+
     ##################################################
     # PUBLIC METHODS THAT RETURN A QUERYSET SUBCLASS #
     ##################################################