Support UUID (#329)

* Add support for UUID

mssql/base.py

@@ -124,7 +124,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         'SmallIntegerField': 'smallint',
         'TextField': 'nvarchar(max)',
         'TimeField': 'time',
-        'UUIDField': 'char(32)',
+        'UUIDField': 'uniqueidentifier',
     }
     data_types_suffix = {
         'AutoField': 'IDENTITY (1, 1)',
@@ -376,7 +376,6 @@ def get_new_connection(self, conn_params):
                         break
                 if not need_to_retry:
                     raise
-
         # Handling values from DATETIMEOFFSET columns
         # source: https://github.com/mkleehammer/pyodbc/wiki/Using-an-Output-Converter-function
         conn.add_output_converter(SQL_TIMESTAMP_WITH_TIMEZONE, handle_datetimeoffset)
@@ -431,6 +430,9 @@ def init_connection_state(self):
         if (options.get('return_rows_bulk_insert', False)):
             self.features_class.can_return_rows_from_bulk_insert = True
 
+        if (options.get('has_native_uuid_field', True)):
+            Database.native_uuid = True
+
         val = self.get_system_datetime
         if isinstance(val, str):
             raise ImproperlyConfigured(

mssql/features.py

@@ -22,7 +22,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     has_json_object_function = False
     has_json_operators = False
     has_native_json_field = False
-    has_native_uuid_field = False
+    has_native_uuid_field = True
     has_real_datatype = True
     has_select_for_update = True
     has_select_for_update_nowait = True
@@ -64,6 +64,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     supports_stored_generated_columns = True
     supports_virtual_generated_columns = True
 
+
     @cached_property
     def has_zoneinfo_database(self):
         with self.connection.cursor() as cursor:

mssql/operations.py

@@ -129,7 +129,7 @@ def convert_floatfield_value(self, value, expression, connection):
 
     def convert_uuidfield_value(self, value, expression, connection):
         if value is not None:
-            value = uuid.UUID(value)
+            value = uuid.UUID(str(value))
         return value
 
     def convert_booleanfield_value(self, value, expression, connection):