fix(1.11): fetch_many() and fetch_all() must not fail

These two methods shall return empty lists when no rows are available.
In MS SQL Server (or pyodcb), they are generating an exception, which -
among other things - breaks standard Django migrations.

Author: Melvyn Sopacua

setup.py

@@ -19,7 +19,7 @@
 
 setup(
     name='django-pyodbc-azure',
-    version='1.11.15.0',
+    version='1.11.15.1',
     description='Django backend for Microsoft SQL Server and Azure SQL Database using pyodbc',
     long_description=open('README.rst').read(),
     author='Michiya Takahashi',

sql_server/pyodbc/base.py

@@ -22,11 +22,10 @@
 
 from django.conf import settings
 from django.db.backends.base.base import BaseDatabaseWrapper
-from django.db.backends.base.validation import BaseDatabaseValidation
+from django.db.utils import ProgrammingError
 from django.utils.encoding import smart_str
 from django.utils.functional import cached_property
 from django.utils.six import binary_type, text_type
-from django.utils.timezone import utc
 
 if hasattr(settings, 'DATABASE_CONNECTION_POOLING'):
     if not settings.DATABASE_CONNECTION_POOLING:
@@ -605,10 +604,16 @@ def fetchone(self):
         return row
 
     def fetchmany(self, chunk):
-        return self.format_rows(self.cursor.fetchmany(chunk))
+        try:
+            return self.format_rows(self.cursor.fetchmany(chunk))
+        except ProgrammingError:
+            return []
 
     def fetchall(self):
-        return self.format_rows(self.cursor.fetchall())
+        try:
+            return self.format_rows(self.cursor.fetchall())
+        except ProgrammingError:
+            return []
 
     def __getattr__(self, attr):
         if attr in self.__dict__: