Queries now translate keys to correct field names

mongoengine/fields.py

@@ -34,6 +34,9 @@ class StringField(BaseField):
             message = 'String value did not match validation regex'
             raise ValidationError(message)
 
+    def lookup_member(self, member_name):
+        return None
+
 
 class IntField(BaseField):
     """An integer field.
@@ -114,6 +117,9 @@ class EmbeddedDocumentField(BaseField):
             raise ValidationError('Invalid embedded document instance '
                                   'provided to an EmbeddedDocumentField')
 
+    def lookup_member(self, member_name):
+        return self.document._fields.get(member_name)
+
 
 class ListField(BaseField):
     """A list field that wraps a standard field, allowing multiple instances
@@ -146,6 +152,9 @@ class ListField(BaseField):
             raise ValidationError('All items in a list field must be of the '
                                   'specified type')
 
+    def lookup_member(self, member_name):
+        return self.field.lookup_member(member_name)
+
 
 class ReferenceField(BaseField):
     """A reference to a document that will be automatically dereferenced on
@@ -194,3 +203,6 @@ class ReferenceField(BaseField):
 
     def validate(self, value):
         assert(isinstance(value, (self.document_type, pymongo.dbref.DBRef)))
+
+    def lookup_member(self, member_name):
+        return self.document_type._fields.get(member_name)

mongoengine/queryset.py

@@ -6,6 +6,10 @@ import pymongo
 __all__ = ['queryset_manager']
 
 
+class InvalidQueryError(Exception):
+    pass
+
+
 class QuerySet(object):
     """A set of results returned from a query. Wraps a MongoDB cursor, 
     providing :class:`~mongoengine.Document` objects as the results.
@@ -38,7 +42,8 @@ class QuerySet(object):
         """Filter the selected documents by calling the 
         :class:`~mongoengine.QuerySet` with a query.
         """
-        self._query.update(QuerySet._transform_query(**query))
+        query = QuerySet._transform_query(_doc_cls=self._document, **query)
+        self._query.update(query)
         return self
 
     @property
@@ -48,7 +53,7 @@ class QuerySet(object):
         return self._cursor_obj
        
     @classmethod
-    def _transform_query(cls, **query):
+    def _transform_query(cls, _doc_cls=None, **query):
         """Transform a query from Django-style format to Mongo format.
         """
         operators = ['neq', 'gt', 'gte', 'lt', 'lte', 'in', 'nin', 'mod',
@@ -63,6 +68,23 @@ class QuerySet(object):
                 op = parts.pop()
                 value = {'$' + op: value}
 
+            # Switch field names to proper names [set in Field(name='foo')]
+            if _doc_cls:
+                field_names = []
+                field = None
+                for field_name in parts:
+                    if field is None:
+                        # Look up first field from the document
+                        field = _doc_cls._fields[field_name]
+                    else:
+                        # Look up subfield on the previous field
+                        field = field.lookup_member(field_name)
+                        if field is None:
+                            raise InvalidQueryError('Cannot resolve field "%s"'
+                                                    % field_name)
+                    field_names.append(field.name)
+                parts = field_names
+
             key = '.'.join(parts)
             if op is None or key not in mongo_query:
                 mongo_query[key] = value

tests/queryset.py

@@ -240,6 +240,35 @@ class QuerySetTest(unittest.TestCase):
 
         BlogPost.drop_collection()
 
+    def test_query_field_name(self):
+        """Ensure that the correct field name is used when querying.
+        """
+        class Comment(EmbeddedDocument):
+            content = StringField(name='commentContent')
+
+        class BlogPost(Document):
+            title = StringField(name='postTitle')
+            comments = ListField(EmbeddedDocumentField(Comment),
+                                 name='postComments')
+                                 
+
+        BlogPost.drop_collection()
+
+        data = {'title': 'Post 1', 'comments': [Comment(content='test')]}
+        BlogPost(**data).save()
+
+        self.assertTrue('postTitle' in 
+                        BlogPost.objects(title=data['title'])._query)
+        self.assertFalse('title' in 
+                         BlogPost.objects(title=data['title'])._query)
+        self.assertEqual(len(BlogPost.objects(title=data['title'])), 1)
+
+        self.assertTrue('postComments.commentContent' in 
+                        BlogPost.objects(comments__content='test')._query)
+        self.assertEqual(len(BlogPost.objects(comments__content='test')), 1)
+
+        BlogPost.drop_collection()
+
     def tearDown(self):
         self.Person.drop_collection()