MySQL Bugs: #71124: callproc function with bytes parameters

Bug #71124	callproc function with bytes parameters
Submitted:	10 Dec 2013 15:18	Modified:	12 Mar 2014 1:33
Reporter:	Bulat Gaifullin	Email Updates:
Status:	Closed	Impact on me:	None
Category:	Connector / Python	Severity:	S1 (Critical)
Version:	1.0.12-1	OS:	Linux (Fedora19)
Assigned to:		CPU Architecture:	Any
Tags:	bytes, connector, python

Description:
If stored procedure has VARBINARY(BINARY) input argument callproc method raises exception.

Error
Traceback (most recent call last):
  File "/usr/lib/python3.3/site-packages/mysql/connector/conversion.py", line 260, in to_python
    return getattr(self, func_name)(value, flddsc)
  File "/usr/lib/python3.3/site-packages/mysql/connector/conversion.py", line 421, in _BLOB_to_python
    return self._STRING_to_python(v, dsc)
  File "/usr/lib/python3.3/site-packages/mysql/connector/conversion.py", line 411, in _STRING_to_python
    return v.decode(self.charset)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xfb in position 0: invalid start byte

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.3/site-packages/mysql/connector/cursor.py", line 297, in _row_to_python
    res += (self._connection.converter.to_python(flddsc, v),)
  File "/usr/lib/python3.3/site-packages/mysql/connector/conversion.py", line 265, in to_python
    raise ValueError("%s (field %s)" % (e, flddsc[0]))
ValueError: 'utf-8' codec can't decode byte 0xfb in position 0: invalid start byte (field @_create_datacenter_arg3)

How to repeat:
CREATE PROCEDURE `proce_with_binary` (data VARBINARY(512))
BEGIN
END;

cursor = mysql.connector.connect(test_database).cursor()
cursor.callproc('proce_with_binary', (b"\xfb"))

Posted by developer:
 
Problem: executing call procedures and getting the result is done by using session variables. These session variables are typeless. Thus, a VARBINARY, we can not handle it correctly and check if it is 'binary' or not.

Posted by developer:
 
A not-so-good workaround, but might help when really needed, is to use "use_unicode=False" for connection dealing with VARBINARY and calling stored procedures.

It is possible to extract types of variables that will be passed to callproc method and use this knowledge to convert SQL-result back to python variables properly in fetchone method.

any updates?

Noted in 1.2.1 changelog.

Connector/Python now permits the type for stored procedure parameters
to be specified. To do this, specify a parameter as a two-item tuple
consisting of the parameter value and type. For more information, see
http://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-callproc.htm...