[MSSQL-Django] Binary() rejects memoryview, breaking Django BinaryField writes and serialization

[bewithgaurav]

Describe the bug

mssql_python.Binary() accepts only str, bytes, and bytearray. It raises TypeError on a memoryview, which pyodbc and most DB-API drivers accept. memoryview is a standard buffer type, and Django's BinaryField hands it straight to the driver, so any BinaryField write or lookup fails under mssql-python.

Exception message:

TypeError: Cannot convert type memoryview to bytes. Binary() only accepts str, bytes, or bytearray objects.

The check is in mssql_python/type.py (Binary(), line 123): it handles bytes, bytearray, and str, then raises for everything else.

To reproduce

Standalone, no database needed:

import mssql_python

mv = memoryview(b"\x01\x02\x03")
mssql_python.Binary(mv)
# TypeError: Cannot convert type memoryview to bytes.
# Binary() only accepts str, bytes, or bytearray objects.

For contrast, pyodbc accepts it:

import pyodbc
pyodbc.Binary(memoryview(b"\x01\x02\x03"))   # returns bytearray(b'\x01\x02\x03')

Through Django on the mssql-django backend, a plain BinaryField save hits the same path and fails:

# class Blob(models.Model): data = models.BinaryField()
Blob.objects.create(data=b"\x00\x01\x02")
#   File ".../django/db/models/fields/__init__.py", in get_db_prep_value
#     return connection.Database.Binary(value)
# TypeError: Cannot convert type memoryview to bytes. ...

Expected behavior

Binary(memoryview(...)) returns the bytes, matching pyodbc and the DB-API convention of accepting buffer-protocol objects. Django BinaryField writes, lookups, and fixture load/dump then work under mssql-python.

Further technical details

Python version: 3.13 (also reproduces on 3.10 through 3.14)
SQL Server version: SQL Server 2022
Operating system: driver-side, OS-independent (seen on macOS and Ubuntu)
mssql-python version: 1.14.0

Additional context

Found while validating mssql-python as a driver for mssql-django. This accounts for 7 of the 9 Django integration-suite failures: 2 in model_fields.test_binaryfield and 5 in serializers.test_data (json/jsonl/python/xml/yaml), since Django's serializers roundtrip BinaryField data through memoryview.

Suggested fix: accept memoryview in Binary() by returning value.tobytes(). One localized change.

[github-actions]

Hi Gaurav Sharma (@bewithgaurav), thank you for opening this issue!

Our team will review it shortly. We aim to triage all new issues within 24-48 hours and get back to you.

If you have additional information to share, please feel free to update the issue.

Thank you for your patience!