pub/mongoengine
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge pull request #2029 from nsuthar0914/patch-1

Browse Source 
Fix limit usage in aggregate
This commit is contained in:
Bastien Gérard 2019-04-07 22:32:31 +02:00 committed by GitHub
commit 4caa58b9ec
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 184 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
mongoengine/queryset/base.py
View File

@ -1200,7 +1200,11 @@ class BaseQuerySet(object):
initial_pipeline.append({'$sort': dict(self._ordering)})
if self._limit is not None:
initial_pipeline.append({'$limit': self._limit})
# As per MongoDB Documentation (https://docs.mongodb.com/manual/reference/operator/aggregation/limit/),
# keeping limit stage right after sort stage is more efficient. But this leads to wrong set of documents
# for a skip stage that might succeed these. So we need to maintain more documents in memory in such a
# case (https://stackoverflow.com/a/24161461).
initial_pipeline.append({'$limit': self._limit + (self._skip or 0)})
if self._skip is not None:
initial_pipeline.append({'$skip': self._skip})

179
tests/queryset/queryset.py
View File

@ -5349,6 +5349,185 @@ class QuerySetTest(unittest.TestCase):
{'_id': None, 'avg': 29, 'total': 2}
])
@requires_mongodb_gte_26
def test_queryset_aggregation_with_skip(self):
class Person(Document):
name = StringField()
age = IntField()
Person.drop_collection()
p1 = Person(name="Isabella Luanna", age=16)
p1.save()
p2 = Person(name="Wilson Junior", age=21)
p2.save()
p3 = Person(name="Sandra Mara", age=37)
p3.save()
data = Person.objects.skip(1).aggregate(
{'$project': {'name': {'$toUpper': '$name'}}}
)
self.assertEqual(list(data), [
{'_id': p2.pk, 'name': "WILSON JUNIOR"},
{'_id': p3.pk, 'name': "SANDRA MARA"}
])
@requires_mongodb_gte_26
def test_queryset_aggregation_with_limit(self):
class Person(Document):
name = StringField()
age = IntField()
Person.drop_collection()
p1 = Person(name="Isabella Luanna", age=16)
p1.save()
p2 = Person(name="Wilson Junior", age=21)
p2.save()
p3 = Person(name="Sandra Mara", age=37)
p3.save()
data = Person.objects.limit(1).aggregate(
{'$project': {'name': {'$toUpper': '$name'}}}
)
self.assertEqual(list(data), [
{'_id': p1.pk, 'name': "ISABELLA LUANNA"}
])
@requires_mongodb_gte_26
def test_queryset_aggregation_with_sort(self):
class Person(Document):
name = StringField()
age = IntField()
Person.drop_collection()
p1 = Person(name="Isabella Luanna", age=16)
p1.save()
p2 = Person(name="Wilson Junior", age=21)
p2.save()
p3 = Person(name="Sandra Mara", age=37)
p3.save()
data = Person.objects.order_by('name').aggregate(
{'$project': {'name': {'$toUpper': '$name'}}}
)
self.assertEqual(list(data), [
{'_id': p1.pk, 'name': "ISABELLA LUANNA"},
{'_id': p3.pk, 'name': "SANDRA MARA"},
{'_id': p2.pk, 'name': "WILSON JUNIOR"}
])
@requires_mongodb_gte_26
def test_queryset_aggregation_with_skip_with_limit(self):
class Person(Document):
name = StringField()
age = IntField()
Person.drop_collection()
p1 = Person(name="Isabella Luanna", age=16)
p1.save()
p2 = Person(name="Wilson Junior", age=21)
p2.save()
p3 = Person(name="Sandra Mara", age=37)
p3.save()
data = Person.objects.skip(1).limit(1).aggregate(
{'$project': {'name': {'$toUpper': '$name'}}}
)
self.assertEqual(list(data), [
{'_id': p2.pk, 'name': "WILSON JUNIOR"},
])
@requires_mongodb_gte_26
def test_queryset_aggregation_with_sort_with_limit(self):
class Person(Document):
name = StringField()
age = IntField()
Person.drop_collection()
p1 = Person(name="Isabella Luanna", age=16)
p1.save()
p2 = Person(name="Wilson Junior", age=21)
p2.save()
p3 = Person(name="Sandra Mara", age=37)
p3.save()
data = Person.objects.order_by('name').limit(2).aggregate(
{'$project': {'name': {'$toUpper': '$name'}}}
)
self.assertEqual(list(data), [
{'_id': p1.pk, 'name': "ISABELLA LUANNA"},
{'_id': p3.pk, 'name': "SANDRA MARA"}
])
@requires_mongodb_gte_26
def test_queryset_aggregation_with_sort_with_skip(self):
class Person(Document):
name = StringField()
age = IntField()
Person.drop_collection()
p1 = Person(name="Isabella Luanna", age=16)
p1.save()
p2 = Person(name="Wilson Junior", age=21)
p2.save()
p3 = Person(name="Sandra Mara", age=37)
p3.save()
data = Person.objects.order_by('name').skip(2).aggregate(
{'$project': {'name': {'$toUpper': '$name'}}}
)
self.assertEqual(list(data), [
{'_id': p2.pk, 'name': "WILSON JUNIOR"}
])
@requires_mongodb_gte_26
def test_queryset_aggregation_with_sort_with_skip_with_limit(self):
class Person(Document):
name = StringField()
age = IntField()
Person.drop_collection()
p1 = Person(name="Isabella Luanna", age=16)
p1.save()
p2 = Person(name="Wilson Junior", age=21)
p2.save()
p3 = Person(name="Sandra Mara", age=37)
p3.save()
data = Person.objects.order_by('name').skip(1).limit(1).aggregate(
{'$project': {'name': {'$toUpper': '$name'}}}
)
self.assertEqual(list(data), [
{'_id': p3.pk, 'name': "SANDRA MARA"}
])
def test_delete_count(self):
[self.Person(name="User {0}".format(i), age=i * 10).save() for i in range(1, 4)]
self.assertEqual(self.Person.objects().delete(), 3) # test ordinary QuerySey delete count