INTPYTHON-348 add support for QuerySet.raw_mql()

- Tim tips and pair w/Jib

Author: aclark4life

django_mongodb/query.py

@@ -319,6 +319,36 @@ def raw_mql(self, raw_query, params=(), translations=None, using=None):
 
 
 class MongoRawQuery(RawQuery):
+
+
+    def __init__(self, sql, using, model, params=()):
+        self.params = params
+        self.sql = sql
+        self.using = using
+        self.cursor = None
+        self.model = model
+
+        # Mirror some properties of a normal query so that
+        # the compiler can be used to process results.
+        self.low_mark, self.high_mark = 0, None  # Used for offset/limit
+        self.extra_select = {}
+        self.annotation_select = {}
+
+    def __iter__(self):
+        # Always execute a new query for a new iterator.
+        # This could be optimized with a cache at the expense of RAM.
+
+        self.cursor = self._execute_query()
+
+        if not connections[self.using].features.can_use_chunked_reads:
+            # If the database can't use chunked reads we need to make sure we
+            # evaluate the entire query up front.
+            result = list(self.cursor)
+        else:
+            result = self.cursor
+
+        return iter(result)
+
     def _execute_query(self):
         connection = connections[self.using]
         params_type = self.params_type
@@ -332,8 +362,19 @@ def _execute_query(self):
         else:
             raise RuntimeError("Unexpected params type: %s" % params_type)
 
-        self.cursor = connection.cursor()
-        self.cursor.execute(self.sql, params)
+        # self.cursor = connection.cursor()
+        # self.cursor.execute(self.sql, params)
+
+        collection = connection.get_collection(self.model._meta.db_table)
+	
+        return collection.aggregate(self.sql)
+
+    def get_columns(self):
+        if self.cursor is None:
+            self._execute_query()
+        converter = connections[self.using].introspection.identifier_converter
+        self.cursor.description = ""
+        return [converter(column_meta[0]) for column_meta in self.cursor.description]
 
 
 class MongoRawQuerySet(RawQuerySet):
@@ -350,5 +391,6 @@ def __init__(
         self.model = model
         self._db = using
         self._hints = hints or {}
-        self.query = query or MongoRawQuery(sql=raw_query, using=self.db, params=params)
+        self.query = query or MongoRawQuery(sql=raw_query, using=self.db, model=self.model, params=params)
         self._result_cache = None
+        self.translations = translations or {}