INTPYTHON-928 Add helpful error messages for Cursor.execute() & executemany()

Author: timgraham

django_mongodb_backend/base.py

@@ -4,7 +4,7 @@
 
 from bson import Decimal128
 from django.core.exceptions import EmptyResultSet, FullResultSet, ImproperlyConfigured
-from django.db import DEFAULT_DB_ALIAS
+from django.db import DEFAULT_DB_ALIAS, NotSupportedError
 from django.db.backends.base.base import BaseDatabaseWrapper
 from django.db.backends.utils import debug_transaction
 from django.utils.asyncio import async_unsafe
@@ -28,14 +28,23 @@
 
 
 class Cursor:
-    """A "nodb" cursor that does nothing except work on a context manager."""
+    """DB-API style cursors aren't supported by MongoDB."""
 
     def __enter__(self):
-        pass
+        return self
 
     def __exit__(self, exception_type, exception_value, exception_traceback):
         pass
 
+    def execute(self, query, args=None):
+        raise NotSupportedError("MongoDB does not support cursor.execute().")
+
+    def executemany(self, query, args):
+        raise NotSupportedError("MongoDB does not support cursor.executemany().")
+
+    def callproc(self, procname, params=None, kparams=None):
+        raise NotSupportedError("MongoDB does not support cursor.callproc().")
+
 
 logger = logging.getLogger("django.db.backends.base")
 

tests/backend_/test_base.py

@@ -1,7 +1,7 @@
 from unittest.mock import patch
 
 from django.core.exceptions import ImproperlyConfigured
-from django.db import connection
+from django.db import NotSupportedError, connection
 from django.db.backends.signals import connection_created
 from django.test import SimpleTestCase, TestCase
 
@@ -146,3 +146,26 @@ def receiver(sender, connection, **kwargs):  # noqa: ARG001
         data.clear()
         connection.connect()
         self.assertEqual(data, {})
+
+
+class CursorTests(TestCase):
+    def test_callproc(self):
+        msg = "MongoDB does not support cursor.callproc()."
+        with self.assertRaisesMessage(NotSupportedError, msg), connection.cursor() as cursor:
+            cursor.callproc("...")
+        with self.assertRaisesMessage(NotSupportedError, msg), connection.cursor() as cursor:
+            cursor.callproc("...", [])
+        with self.assertRaisesMessage(NotSupportedError, msg), connection.cursor() as cursor:
+            cursor.callproc("...", [], [])
+
+    def test_execute(self):
+        msg = "MongoDB does not support cursor.execute()."
+        with self.assertRaisesMessage(NotSupportedError, msg), connection.cursor() as cursor:
+            cursor.execute("...")
+        with self.assertRaisesMessage(NotSupportedError, msg), connection.cursor() as cursor:
+            cursor.execute("...", [])
+
+    def test_executemany(self):
+        msg = "MongoDB does not support cursor.executemany()."
+        with self.assertRaisesMessage(NotSupportedError, msg), connection.cursor() as cursor:
+            cursor.executemany("...", [])