From c38faebc25a4a4bfa749d97005a43e6bbe6c0be3 Mon Sep 17 00:00:00 2001
From: James Punteney <punteney@gmail.com>
Date: Sat, 16 Jan 2010 13:21:16 -0500
Subject: [PATCH] Adding a get method to the queryset that raises exceptions if
 more or less than one item is returned

---
 mongoengine/queryset.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/mongoengine/queryset.py b/mongoengine/queryset.py
index 06c82cf9..7d89a447 100644
--- a/mongoengine/queryset.py
+++ b/mongoengine/queryset.py
@@ -18,6 +18,11 @@ class InvalidQueryError(Exception):
 class OperationError(Exception):
     pass
 
+class MultipleObjectsReturned(Exception):
+    pass
+
+class DoesNotExist(Exception):
+    pass
 
 class Q(object):
     
@@ -290,6 +295,20 @@ class QuerySet(object):
 
         return mongo_query
 
+    def get(self):
+        """Retrieve the the matching object raising 
+        'MultipleObjectsReturned' or 'DoesNotExist' exceptions
+        if multiple or no results are found.
+        """
+        count = self.count()
+        if count == 1:
+            return self[0]
+        elif count > 1:
+            raise MultipleObjectsReturned
+        else:
+            raise DoesNotExist
+
+
     def first(self):
         """Retrieve the first object matching the query.
         """