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 1/3] 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.
         """

From 47e4dd40cd69f314f59703abb124f58268355f1f Mon Sep 17 00:00:00 2001
From: James Punteney <punteney@gmail.com>
Date: Sat, 16 Jan 2010 13:24:10 -0500
Subject: [PATCH 2/3] Making the query actually get called for get

---
 mongoengine/queryset.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mongoengine/queryset.py b/mongoengine/queryset.py
index 7d89a447..92d20315 100644
--- a/mongoengine/queryset.py
+++ b/mongoengine/queryset.py
@@ -295,11 +295,12 @@ class QuerySet(object):
 
         return mongo_query
 
-    def get(self):
+    def get(self, *q_objs, **query):
         """Retrieve the the matching object raising 
         'MultipleObjectsReturned' or 'DoesNotExist' exceptions
         if multiple or no results are found.
         """
+        self.__call__(*q_objs, **query)
         count = self.count()
         if count == 1:
             return self[0]

From e0becc109d1f6a236e500e65b4f8ff30b34b9e6d Mon Sep 17 00:00:00 2001
From: James Punteney <punteney@gmail.com>
Date: Sat, 16 Jan 2010 14:51:13 -0500
Subject: [PATCH 3/3] Adding tests to test the get query

---
 mongoengine/queryset.py |  1 -
 tests/queryset.py       | 23 ++++++++++++++++++++++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/mongoengine/queryset.py b/mongoengine/queryset.py
index 92d20315..4a563b53 100644
--- a/mongoengine/queryset.py
+++ b/mongoengine/queryset.py
@@ -14,7 +14,6 @@ REPR_OUTPUT_SIZE = 20
 class InvalidQueryError(Exception):
     pass
 
-
 class OperationError(Exception):
     pass
 
diff --git a/tests/queryset.py b/tests/queryset.py
index 93dc0747..bf8af758 100644
--- a/tests/queryset.py
+++ b/tests/queryset.py
@@ -2,7 +2,7 @@ import unittest
 import pymongo
 from datetime import datetime
 
-from mongoengine.queryset import QuerySet
+from mongoengine.queryset import QuerySet, MultipleObjectsReturned, DoesNotExist
 from mongoengine import *
 
 
@@ -135,6 +135,27 @@ class QuerySetTest(unittest.TestCase):
         person = self.Person.objects.with_id(person1.id)
         self.assertEqual(person.name, "User A")
 
+    def test_find_only_one(self):
+        """Ensure that a query using find_one returns a valid result.
+        """
+        # Try retrieving when no objects exists
+        self.assertRaises(DoesNotExist, self.Person.objects.get)
+
+        person1 = self.Person(name="User A", age=20)
+        person1.save()
+        person2 = self.Person(name="User B", age=30)
+        person2.save()
+
+        # Retrieve the first person from the database
+        self.assertRaises(MultipleObjectsReturned, self.Person.objects.get)
+
+        # Use a query to filter the people found to just person2
+        person = self.Person.objects.get(age=30)
+        self.assertEqual(person.name, "User B")
+
+        person = self.Person.objects.get(age__lt=30)
+        self.assertEqual(person.name, "User A")
+
     def test_filter_chaining(self):
         """Ensure filters can be chained together.
         """