use an external sphinx rtd theme

.travis.yml

@@ -16,6 +16,7 @@ python:
 - 2.7
 - 3.5
 - pypy
+- pypy3
 
 env:
 - MONGODB=2.6 PYMONGO=2.7

docs/changelog.rst

@@ -6,12 +6,6 @@ Development
 ===========
 - (Fill this out as you fix issues and develop your features).
 
-Changes in 0.14.0
-=================
-- BREAKING CHANGE: Removed the `coerce_types` param from `QuerySet.as_pymongo` #1549
-- POTENTIAL BREAKING CHANGE: Made EmbeddedDocument not hashable by default #1528
-- Improved code quality #1531, #1540, #1541, #1547
-
 Changes in 0.13.0
 =================
 - POTENTIAL BREAKING CHANGE: Added Unicode support to the `EmailField`, see

docs/upgrade.rst

@@ -6,18 +6,6 @@ Development
 ***********
 (Fill this out whenever you introduce breaking changes to MongoEngine)
 
-0.14.0
-******
-This release includes a few bug fixes and a significant code cleanup. The most
-important change is that `QuerySet.as_pymongo` no longer supports a
-`coerce_types` mode. If you used it in the past, a) please let us know of your
-use case, b) you'll need to override `as_pymongo` to get the desired outcome.
-
-This release also makes the EmbeddedDocument not hashable by default. If you
-use embedded documents in sets or dictionaries, you might have to override
-`__hash__` and implement a hashing logic specific to your use case. See #1528
-for the reason behind this change.
-
 0.13.0
 ******
 This release adds Unicode support to the `EmailField` and changes its

mongoengine/__init__.py

@@ -23,7 +23,7 @@ __all__ = (list(document.__all__) + list(fields.__all__) +
            list(signals.__all__) + list(errors.__all__))
 
 
-VERSION = (0, 14, 0)
+VERSION = (0, 13, 0)
 
 
 def get_version():

mongoengine/base/fields.py

@@ -81,14 +81,7 @@ class BaseField(object):
         self.sparse = sparse
         self._owner_document = None
 
-        # Make sure db_field is a string (if it's explicitly defined).
+        # Validate the db_field
-        if (
-            self.db_field is not None and
-            not isinstance(self.db_field, six.string_types)
-        ):
-            raise TypeError('db_field should be a string.')
-
-        # Make sure db_field doesn't contain any forbidden characters.
         if isinstance(self.db_field, six.string_types) and (
             '.' in self.db_field or
             '\0' in self.db_field or

mongoengine/dereference.py

@@ -1,3 +1,4 @@
+from collections import OrderedDict
 from bson import DBRef, SON
 import six
 
@@ -201,6 +202,10 @@ class DeReference(object):
             as_tuple = isinstance(items, tuple)
             iterator = enumerate(items)
             data = []
+        elif isinstance(items, OrderedDict):
+            is_list = False
+            iterator = items.iteritems()
+            data = OrderedDict()
         else:
             is_list = False
             iterator = items.iteritems()

mongoengine/document.py

@@ -300,7 +300,7 @@ class Document(BaseDocument):
         created.
 
         :param force_insert: only try to create a new document, don't allow
-            updates of existing documents.
+            updates of existing documents
         :param validate: validates the document; set to ``False`` to skip.
         :param clean: call the document clean method, requires `validate` to be
             True.
@@ -441,21 +441,6 @@ class Document(BaseDocument):
 
         return object_id
 
-    def _get_update_doc(self):
-        """Return a dict containing all the $set and $unset operations
-        that should be sent to MongoDB based on the changes made to this
-        Document.
-        """
-        updates, removals = self._delta()
-
-        update_doc = {}
-        if updates:
-            update_doc['$set'] = updates
-        if removals:
-            update_doc['$unset'] = removals
-
-        return update_doc
-
     def _save_update(self, doc, save_condition, write_concern):
         """Update an existing document.
 
@@ -481,10 +466,15 @@ class Document(BaseDocument):
                 val = val[ak]
             select_dict['.'.join(actual_key)] = val
 
-        update_doc = self._get_update_doc()
+        updates, removals = self._delta()
-        if update_doc:
+        update_query = {}
+        if updates:
+            update_query['$set'] = updates
+        if removals:
+            update_query['$unset'] = removals
+        if updates or removals:
             upsert = save_condition is None
-            last_error = collection.update(select_dict, update_doc,
+            last_error = collection.update(select_dict, update_query,
                                            upsert=upsert, **write_concern)
             if not upsert and last_error['n'] == 0:
                 raise SaveConditionError('Race condition preventing'

mongoengine/fields.py

@@ -6,6 +6,7 @@ import socket
 import time
 import uuid
 import warnings
+from collections import Mapping
 from operator import itemgetter
 
 from bson import Binary, DBRef, ObjectId, SON
@@ -704,6 +705,14 @@ class DynamicField(BaseField):
 
     Used by :class:`~mongoengine.DynamicDocument` to handle dynamic data"""
 
+    def __init__(self, container_class=dict, *args, **kwargs):
+        self._container_cls = container_class
+        if not issubclass(self._container_cls, Mapping):
+            self.error('The class that is specified in `container_class` parameter '
+                       'must be a subclass of `dict`.')
+
+        super(DynamicField, self).__init__(*args, **kwargs)
+
     def to_mongo(self, value, use_db_field=True, fields=None):
         """Convert a Python type to a MongoDB compatible type.
         """
@@ -729,7 +738,7 @@ class DynamicField(BaseField):
             is_list = True
             value = {k: v for k, v in enumerate(value)}
 
-        data = {}
+        data = self._container_cls()
         for k, v in value.iteritems():
             data[k] = self.to_mongo(v, use_db_field, fields)
 

mongoengine/queryset/base.py

@@ -67,6 +67,7 @@ class BaseQuerySet(object):
         self._scalar = []
         self._none = False
         self._as_pymongo = False
+        self._as_pymongo_coerce = False
         self._search_text = None
 
         # If inheritance is allowed, only return instances and instances of
@@ -727,12 +728,11 @@ class BaseQuerySet(object):
                 '%s is not a subclass of BaseQuerySet' % new_qs.__name__)
 
         copy_props = ('_mongo_query', '_initial_query', '_none', '_query_obj',
-                      '_where_clause', '_loaded_fields', '_ordering',
+                      '_where_clause', '_loaded_fields', '_ordering', '_snapshot',
-                      '_snapshot', '_timeout', '_class_check', '_slave_okay',
+                      '_timeout', '_class_check', '_slave_okay', '_read_preference',
-                      '_read_preference', '_iter', '_scalar', '_as_pymongo',
+                      '_iter', '_scalar', '_as_pymongo', '_as_pymongo_coerce',
                       '_limit', '_skip', '_hint', '_auto_dereference',
-                      '_search_text', 'only_fields', '_max_time_ms',
+                      '_search_text', 'only_fields', '_max_time_ms', '_comment')
-                      '_comment')
 
         for prop in copy_props:
             val = getattr(self, prop)
@@ -939,8 +939,7 @@ class BaseQuerySet(object):
 
             posts = BlogPost.objects(...).fields(slice__comments=5)
 
-        :param kwargs: A set of keyword arguments identifying what to
+        :param kwargs: A set keywors arguments identifying what to include.
-            include, exclude, or slice.
 
         .. versionadded:: 0.5
         """
@@ -1129,15 +1128,16 @@ class BaseQuerySet(object):
         """An alias for scalar"""
         return self.scalar(*fields)
 
-    def as_pymongo(self):
+    def as_pymongo(self, coerce_types=False):
         """Instead of returning Document instances, return raw values from
         pymongo.
 
-        This method is particularly useful if you don't need dereferencing
+        :param coerce_types: Field types (if applicable) would be use to
-        and care primarily about the speed of data retrieval.
+            coerce types.
         """
         queryset = self.clone()
         queryset._as_pymongo = True
+        queryset._as_pymongo_coerce = coerce_types
         return queryset
 
     def max_time_ms(self, ms):
@@ -1799,25 +1799,59 @@ class BaseQuerySet(object):
 
         return tuple(data)
 
-    def _get_as_pymongo(self, doc):
+    def _get_as_pymongo(self, row):
-        """Clean up a PyMongo doc, removing fields that were only fetched
+        # Extract which fields paths we should follow if .fields(...) was
-        for the sake of MongoEngine's implementation, and return it.
+        # used. If not, handle all fields.
-        """
+        if not getattr(self, '__as_pymongo_fields', None):
-        # Always remove _cls as a MongoEngine's implementation detail.
+            self.__as_pymongo_fields = []
-        if '_cls' in doc:
-            del doc['_cls']
 
-        # If the _id was not included in a .only or was excluded in a .exclude,
+            for field in self._loaded_fields.fields - set(['_cls']):
-        # remove it from the doc (we always fetch it so that we can properly
+                self.__as_pymongo_fields.append(field)
-        # construct documents).
+                while '.' in field:
-        fields = self._loaded_fields
+                    field, _ = field.rsplit('.', 1)
-        if fields and '_id' in doc and (
+                    self.__as_pymongo_fields.append(field)
-            (fields.value == QueryFieldList.ONLY and '_id' not in fields.fields) or
-            (fields.value == QueryFieldList.EXCLUDE and '_id' in fields.fields)
-        ):
-            del doc['_id']
 
-        return doc
+        all_fields = not self.__as_pymongo_fields
+
+        def clean(data, path=None):
+            path = path or ''
+
+            if isinstance(data, dict):
+                new_data = {}
+                for key, value in data.iteritems():
+                    new_path = '%s.%s' % (path, key) if path else key
+
+                    if all_fields:
+                        include_field = True
+                    elif self._loaded_fields.value == QueryFieldList.ONLY:
+                        include_field = new_path in self.__as_pymongo_fields
+                    else:
+                        include_field = new_path not in self.__as_pymongo_fields
+
+                    if include_field:
+                        new_data[key] = clean(value, path=new_path)
+                data = new_data
+            elif isinstance(data, list):
+                data = [clean(d, path=path) for d in data]
+            else:
+                if self._as_pymongo_coerce:
+                    # If we need to coerce types, we need to determine the
+                    # type of this field and use the corresponding
+                    # .to_python(...)
+                    EmbeddedDocumentField = _import_class('EmbeddedDocumentField')
+
+                    obj = self._document
+                    for chunk in path.split('.'):
+                        obj = getattr(obj, chunk, None)
+                        if obj is None:
+                            break
+                        elif isinstance(obj, EmbeddedDocumentField):
+                            obj = obj.document_type
+                    if obj and data is not None:
+                        data = obj.to_python(data)
+            return data
+
+        return clean(row)
 
     def _sub_js_fields(self, code):
         """When fields are specified with [~fieldname] syntax, where

tests/document/instance.py

@@ -242,7 +242,7 @@ class InstanceTest(unittest.TestCase):
         Zoo.drop_collection()
 
         class Zoo(Document):
-            animals = ListField(GenericReferenceField())
+            animals = ListField(GenericReferenceField(Animal))
 
         # Save a reference to each animal
         zoo = Zoo(animals=Animal.objects)

tests/fields/fields.py

@@ -5,9 +5,11 @@ import uuid
 import math
 import itertools
 import re
+import pymongo
 import sys
 
 from nose.plugins.skip import SkipTest
+from collections import OrderedDict
 import six
 
 try:
@@ -26,9 +28,12 @@ except ImportError:
 from mongoengine import *
 from mongoengine.connection import get_db
 from mongoengine.base import (BaseDict, BaseField, EmbeddedDocumentList,
-                              _document_registry)
+                              _document_registry, TopLevelDocumentMetaclass)
 
-from tests.utils import MongoDBTestCase
+from tests.utils import MongoDBTestCase, MONGO_TEST_DB
+from mongoengine.python_support import IS_PYMONGO_3
+if IS_PYMONGO_3:
+    from bson import CodecOptions
 
 __all__ = ("FieldTest", "EmbeddedDocumentListFieldTestCase")
 
@@ -4183,6 +4188,67 @@ class EmbeddedDocumentListFieldTestCase(MongoDBTestCase):
         self.assertTrue(hasattr(CustomData.c_field, 'custom_data'))
         self.assertEqual(custom_data['a'], CustomData.c_field.custom_data['a'])
 
+    def test_dynamicfield_with_container_class(self):
+        """
+        Tests that object can be stored in order by DynamicField class
+        with container_class parameter.
+        """
+        raw_data = [('d', 1), ('c', 2), ('b', 3), ('a', 4)]
+
+        class Doc(Document):
+            ordered_data = DynamicField(container_class=OrderedDict)
+            unordered_data = DynamicField()
+
+        Doc.drop_collection()
+
+        doc = Doc(ordered_data=OrderedDict(raw_data), unordered_data=dict(raw_data)).save()
+
+        # checks that the data is in order
+        self.assertEqual(type(doc.ordered_data), OrderedDict)
+        self.assertEqual(type(doc.unordered_data), dict)
+        self.assertEqual(','.join(doc.ordered_data.keys()), 'd,c,b,a')
+
+        # checks that the data is stored to the database in order
+        pymongo_db = pymongo.MongoClient()[MONGO_TEST_DB]
+        if IS_PYMONGO_3:
+            codec_option = CodecOptions(document_class=OrderedDict)
+            db_doc = pymongo_db.doc.with_options(codec_options=codec_option).find_one()
+        else:
+            db_doc = pymongo_db.doc.find_one(as_class=OrderedDict)
+
+        self.assertEqual(','.join(doc.ordered_data.keys()), 'd,c,b,a')
+
+    def test_dynamicfield_with_wrong_container_class(self):
+        with self.assertRaises(ValidationError):
+            class DocWithInvalidField:
+                data = DynamicField(container_class=list)
+
+    def test_dynamicfield_with_wrong_container_class_and_reload_docuemnt(self):
+        # This is because 'codec_options' is supported on pymongo3 or later
+        if IS_PYMONGO_3:
+            class OrderedDocument(Document):
+                my_metaclass = TopLevelDocumentMetaclass
+                __metaclass__ = TopLevelDocumentMetaclass
+
+                @classmethod
+                def _get_collection(cls):
+                    collection = super(OrderedDocument, cls)._get_collection()
+                    opts = CodecOptions(document_class=OrderedDict)
+
+                    return collection.with_options(codec_options=opts)
+
+            raw_data = [('d', 1), ('c', 2), ('b', 3), ('a', 4)]
+
+            class Doc(OrderedDocument):
+                data = DynamicField(container_class=OrderedDict)
+
+            Doc.drop_collection()
+
+            doc = Doc(data=OrderedDict(raw_data)).save()
+            doc.reload()
+
+            self.assertEqual(type(doc.data), OrderedDict)
+            self.assertEqual(','.join(doc.data.keys()), 'd,c,b,a')
 
 class CachedReferenceFieldTest(MongoDBTestCase):
 

tests/queryset/queryset.py

@@ -917,9 +917,7 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(Blog.objects.count(), 3)
 
     def test_get_changed_fields_query_count(self):
-        """Make sure we don't perform unnecessary db operations when
+
-        none of document's fields were updated.
-        """
         class Person(Document):
             name = StringField()
             owns = ListField(ReferenceField('Organization'))
@@ -927,8 +925,8 @@ class QuerySetTest(unittest.TestCase):
 
         class Organization(Document):
             name = StringField()
-            owner = ReferenceField(Person)
+            owner = ReferenceField('Person')
-            employees = ListField(ReferenceField(Person))
+            employees = ListField(ReferenceField('Person'))
 
         class Project(Document):
             name = StringField()
@@ -947,35 +945,35 @@ class QuerySetTest(unittest.TestCase):
         with query_counter() as q:
             self.assertEqual(q, 0)
 
-            # Fetching a document should result in a query.
+            fresh_o1 = Organization.objects.get(id=o1.id)
-            org = Organization.objects.get(id=o1.id)
+            self.assertEqual(1, q)
-            self.assertEqual(q, 1)
+            fresh_o1._get_changed_fields()
+            self.assertEqual(1, q)
 
-            # Checking changed fields of a newly fetched document should not
-            # result in a query.
-            org._get_changed_fields()
-            self.assertEqual(q, 1)
-
-        # Saving a doc without changing any of its fields should not result
-        # in a query (with or without cascade=False).
-        org = Organization.objects.get(id=o1.id)
         with query_counter() as q:
-            org.save()
             self.assertEqual(q, 0)
 
-        org = Organization.objects.get(id=o1.id)
+            fresh_o1 = Organization.objects.get(id=o1.id)
+            fresh_o1.save()   # No changes, does nothing
+
+            self.assertEqual(q, 1)
+
         with query_counter() as q:
-            org.save(cascade=False)
             self.assertEqual(q, 0)
 
-        # Saving a doc after you append a reference to it should result in
+            fresh_o1 = Organization.objects.get(id=o1.id)
-        # two db operations (a query for the reference and an update).
+            fresh_o1.save(cascade=False)  # No changes, does nothing
-        # TODO dereferencing of p2 shouldn't be necessary.
+
-        org = Organization.objects.get(id=o1.id)
+            self.assertEqual(q, 1)
+
         with query_counter() as q:
-            org.employees.append(p2)  # dereferences p2
+            self.assertEqual(q, 0)
-            org.save()  # saves the org
+
-            self.assertEqual(q, 2)
+            fresh_o1 = Organization.objects.get(id=o1.id)
+            fresh_o1.employees.append(p2)  # Dereferences
+            fresh_o1.save(cascade=False)   # Saves
+
+            self.assertEqual(q, 3)
 
     @skip_pymongo3
     def test_slave_okay(self):
@@ -4047,35 +4045,6 @@ class QuerySetTest(unittest.TestCase):
         plist = list(Person.objects.scalar('name', 'state'))
         self.assertEqual(plist, [(u'Wilson JR', s1)])
 
-    def test_generic_reference_field_with_only_and_as_pymongo(self):
-        class TestPerson(Document):
-            name = StringField()
-
-        class TestActivity(Document):
-            name = StringField()
-            owner = GenericReferenceField()
-
-        TestPerson.drop_collection()
-        TestActivity.drop_collection()
-
-        person = TestPerson(name='owner')
-        person.save()
-
-        a1 = TestActivity(name='a1', owner=person)
-        a1.save()
-
-        activity = TestActivity.objects(owner=person).scalar('id', 'owner').no_dereference().first()
-        self.assertEqual(activity[0], a1.pk)
-        self.assertEqual(activity[1]['_ref'], DBRef('test_person', person.pk))
-
-        activity = TestActivity.objects(owner=person).only('id', 'owner')[0]
-        self.assertEqual(activity.pk, a1.pk)
-        self.assertEqual(activity.owner, person)
-
-        activity = TestActivity.objects(owner=person).only('id', 'owner').as_pymongo().first()
-        self.assertEqual(activity['_id'], a1.pk)
-        self.assertTrue(activity['owner']['_ref'], DBRef('test_person', person.pk))
-
     def test_scalar_db_field(self):
 
         class TestDoc(Document):
@@ -4421,44 +4390,21 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(doc_objects, Doc.objects.from_json(json_data))
 
     def test_as_pymongo(self):
-        from decimal import Decimal
 
-        class LastLogin(EmbeddedDocument):
+        from decimal import Decimal
-            location = StringField()
-            ip = StringField()
 
         class User(Document):
             id = ObjectIdField('_id')
             name = StringField()
             age = IntField()
             price = DecimalField()
-            last_login = EmbeddedDocumentField(LastLogin)
 
         User.drop_collection()
-
+        User(name="Bob Dole", age=89, price=Decimal('1.11')).save()
-        User.objects.create(name="Bob Dole", age=89, price=Decimal('1.11'))
+        User(name="Barack Obama", age=51, price=Decimal('2.22')).save()
-        User.objects.create(
-            name="Barack Obama",
-            age=51,
-            price=Decimal('2.22'),
-            last_login=LastLogin(
-                location='White House',
-                ip='104.107.108.116'
-            )
-        )
-
-        results = User.objects.as_pymongo()
-        self.assertEqual(
-            set(results[0].keys()),
-            set(['_id', 'name', 'age', 'price'])
-        )
-        self.assertEqual(
-            set(results[1].keys()),
-            set(['_id', 'name', 'age', 'price', 'last_login'])
-        )
 
         results = User.objects.only('id', 'name').as_pymongo()
-        self.assertEqual(set(results[0].keys()), set(['_id', 'name']))
+        self.assertEqual(sorted(results[0].keys()), sorted(['_id', 'name']))
 
         users = User.objects.only('name', 'price').as_pymongo()
         results = list(users)
@@ -4469,20 +4415,16 @@ class QuerySetTest(unittest.TestCase):
         self.assertEqual(results[1]['name'], 'Barack Obama')
         self.assertEqual(results[1]['price'], 2.22)
 
-        users = User.objects.only('name', 'last_login').as_pymongo()
+        # Test coerce_types
+        users = User.objects.only(
+            'name', 'price').as_pymongo(coerce_types=True)
         results = list(users)
         self.assertTrue(isinstance(results[0], dict))
         self.assertTrue(isinstance(results[1], dict))
-        self.assertEqual(results[0], {
+        self.assertEqual(results[0]['name'], 'Bob Dole')
-            'name': 'Bob Dole'
+        self.assertEqual(results[0]['price'], Decimal('1.11'))
-        })
+        self.assertEqual(results[1]['name'], 'Barack Obama')
-        self.assertEqual(results[1], {
+        self.assertEqual(results[1]['price'], Decimal('2.22'))
-            'name': 'Barack Obama',
-            'last_login': {
-                'location': 'White House',
-                'ip': '104.107.108.116'
-            }
-        })
 
     def test_as_pymongo_json_limit_fields(self):
 
@@ -4646,6 +4588,7 @@ class QuerySetTest(unittest.TestCase):
 
     def test_no_cache(self):
         """Ensure you can add meta data to file"""
+
         class Noddy(Document):
             fields = DictField()
 
@@ -4663,19 +4606,15 @@ class QuerySetTest(unittest.TestCase):
 
         self.assertEqual(len(list(docs)), 100)
 
-        # Can't directly get a length of a no-cache queryset.
         with self.assertRaises(TypeError):
             len(docs)
 
-        # Another iteration over the queryset should result in another db op.
         with query_counter() as q:
+            self.assertEqual(q, 0)
             list(docs)
             self.assertEqual(q, 1)
-
-        # ... and another one to double-check.
-        with query_counter() as q:
             list(docs)
-            self.assertEqual(q, 1)
+            self.assertEqual(q, 2)
 
     def test_nested_queryset_iterator(self):
         # Try iterating the same queryset twice, nested.

tests/test_dereference.py

@@ -2,10 +2,15 @@
 import unittest
 
 from bson import DBRef, ObjectId
+from collections import OrderedDict
 
 from mongoengine import *
 from mongoengine.connection import get_db
 from mongoengine.context_managers import query_counter
+from mongoengine.python_support import IS_PYMONGO_3
+from mongoengine.base import TopLevelDocumentMetaclass
+if IS_PYMONGO_3:
+    from bson import CodecOptions
 
 
 class FieldTest(unittest.TestCase):
@@ -1287,5 +1292,70 @@ class FieldTest(unittest.TestCase):
 
             self.assertEqual(q, 2)
 
+    def test_dynamic_field_dereference(self):
+        class Merchandise(Document):
+            name = StringField()
+            price = IntField()
+
+        class Store(Document):
+            merchandises = DynamicField()
+
+        Merchandise.drop_collection()
+        Store.drop_collection()
+
+        merchandises = {
+            '#1': Merchandise(name='foo', price=100).save(),
+            '#2': Merchandise(name='bar', price=120).save(),
+            '#3': Merchandise(name='baz', price=110).save(),
+        }
+        Store(merchandises=merchandises).save()
+
+        store = Store.objects().first()
+        for obj in store.merchandises.values():
+            self.assertFalse(isinstance(obj, Merchandise))
+
+        store.select_related()
+        for obj in store.merchandises.values():
+            self.assertTrue(isinstance(obj, Merchandise))
+
+    def test_dynamic_field_dereference_with_ordering_guarantee_on_pymongo3(self):
+        # This is because 'codec_options' is supported on pymongo3 or later
+        if IS_PYMONGO_3:
+            class OrderedDocument(Document):
+                my_metaclass = TopLevelDocumentMetaclass
+                __metaclass__ = TopLevelDocumentMetaclass
+
+                @classmethod
+                def _get_collection(cls):
+                    collection = super(OrderedDocument, cls)._get_collection()
+                    opts = CodecOptions(document_class=OrderedDict)
+
+                    return collection.with_options(codec_options=opts)
+
+            class Merchandise(Document):
+                name = StringField()
+                price = IntField()
+
+            class Store(OrderedDocument):
+                merchandises = DynamicField(container_class=OrderedDict)
+
+            Merchandise.drop_collection()
+            Store.drop_collection()
+
+            merchandises = OrderedDict()
+            merchandises['#1'] = Merchandise(name='foo', price=100).save()
+            merchandises['#2'] = Merchandise(name='bar', price=120).save()
+            merchandises['#3'] = Merchandise(name='baz', price=110).save()
+
+            Store(merchandises=merchandises).save()
+
+            store = Store.objects().first()
+
+            store.select_related()
+
+            # confirms that the load data order is same with the one at storing
+            self.assertTrue(type(store.merchandises), OrderedDict)
+            self.assertEqual(','.join(store.merchandises.keys()), '#1,#2,#3')
+
 if __name__ == '__main__':
     unittest.main()