Context

Django provides the following methods to execute raw SQL queries:

with connection.cursor() as cursor:
    cursor.executemany(query, args)
    cursor.execute(query, args)

With MongoDB, this crashes:

  File "/home/tim/code/django/tests/backends/tests.py", line 330, in create_squares
    cursor.executemany(query, args)
    ^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'executemany'

Definition of done

execute() and execute_many() stub methods that raise django.db.NotSupportedError must be added to django-mongodb-backend's Cursor.

(I believe it's unnecessary to raise errors for the reading methods [fetchone, fetchmany, fetchall, nextset] since these would only be called after the execute methods.)