[soc2010/query-refactor] Implemented F() expressions for MongoDB.

git-svn-id: http://code.djangoproject.com/svn/django/branches/soc2010/query-refactor@13430 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/mongodb/compiler.py

@@ -2,6 +2,7 @@ import re
 
 from pymongo import ASCENDING, DESCENDING
 
+from django.db.models import F
 from django.db.models.sql.datastructures import FullResultSet, EmptyResultSet
 
 
@@ -153,8 +154,25 @@ class SQLUpdateCompiler(SQLCompiler):
         filters = self.get_filters(self.query.where)
         # TODO: Don't use set for everything, use INC and such where
         # appropriate.
+        vals = {}
+        for field, o, value in self.query.values:
+            if hasattr(value, "evaluate"):
+                assert value.connector in (value.ADD, value.SUB)
+                assert not value.negated
+                assert not value.subtree_parents
+                lhs, rhs = value.children
+                if isinstance(lhs, F):
+                    assert not isinstance(rhs, F)
+                    if value.connector == value.SUB:
+                        rhs = -rhs
+                else:
+                    assert value.connector == value.ADD
+                    rhs, lhs = lhs, rhs
+                vals.setdefault("$inc", {})[lhs.name] = rhs
+            else:
+                vals.setdefault("$set", {})[field.column] = value
         return self.connection.db[self.query.model._meta.db_table].update(
             filters,
-            {"$set": dict((f.column, val) for f, o, val in self.query.values)},
+            vals,
             multi=True
         )

django/db/models/query.py

@@ -8,7 +8,8 @@ from itertools import izip
 from django.db import connections, router, transaction, IntegrityError
 from django.db.models.aggregates import Aggregate
 from django.db.models.fields import DateField
-from django.db.models.query_utils import Q, select_related_descend, CollectedObjects, CyclicDependency, deferred_class_factory, InvalidQuery
+from django.db.models.query_utils import (Q, select_related_descend,
+    CollectedObjects, CyclicDependency, deferred_class_factory, InvalidQuery)
 from django.db.models import signals, sql
 from django.utils.copycompat import deepcopy
 
@@ -464,7 +465,7 @@ class QuerySet(object):
         else:
             forced_managed = False
         try:
-            rows = query.get_compiler(self.db).execute_sql(None)
+            rows = query.get_compiler(self.db).update(None)
             if forced_managed:
                 transaction.commit(using=self.db)
             else:

tests/regressiontests/mongodb/models.py

@@ -5,6 +5,7 @@ class Artist(models.Model):
     id = models.NativeAutoField(primary_key=True)
     name = models.CharField(max_length=255)
     good = models.BooleanField()
+    age = models.IntegerField(null=True)
     
     current_group = models.ForeignKey("Group", null=True)
     

tests/regressiontests/mongodb/tests.py

@@ -1,4 +1,4 @@
-from django.db.models import Count
+from django.db.models import Count, F
 from django.test import TestCase
 
 from models import Artist, Group
@@ -27,6 +27,28 @@ class MongoTestCase(TestCase):
         l = Artist.objects.get(pk=pk)
         self.assertTrue(not l.good)
     
+    def test_bulk_update(self):
+        # Doesn't actually do an op on more than 1 item, but it's the bulk
+        # update syntax nonetheless
+        v = Artist.objects.create(name="Van Morrison", good=False)
+        # How do you make a mistake like this, I don't know...
+        Artist.objects.filter(pk=v.pk).update(good=True)
+        self.assertTrue(Artist.objects.get(pk=v.pk).good)
+    
+    def test_f_expressions(self):
+        k = Artist.objects.create(name="Keb' Mo'", age=57, good=True)
+        # Birthday!
+        Artist.objects.filter(pk=k.pk).update(age=F("age") + 1)
+        self.assertEqual(Artist.objects.get(pk=k.pk).age, 58)
+        
+        # Backwards birthday
+        Artist.objects.filter(pk=k.pk).update(age=F("age") - 1)
+        self.assertEqual(Artist.objects.get(pk=k.pk).age, 57)
+        
+        # Birthday again!
+        Artist.objects.filter(pk=k.pk).update(age=1 + F("age"))
+        self.assertEqual(Artist.objects.get(pk=k.pk).age, 58)
+    
     def test_count(self):
         Artist.objects.create(name="Billy Joel", good=True)
         Artist.objects.create(name="John Mellencamp", good=True)
@@ -121,7 +143,7 @@ class MongoTestCase(TestCase):
         
         self.assertQuerysetEqual(
             Artist.objects.values(), [
-                {"name": "Steve Perry", "good": True, "current_group_id": None, "id": a.pk},
+                {"name": "Steve Perry", "good": True, "current_group_id": None, "id": a.pk, "age": None},
             ],
             lambda a: a,
         )