FIX: TDS Errors in a Multithreaded ODBC Application

 Last reviewed: October 29, 1997
Article ID: Q154295
2.65 WINDOWS kbusage kbinterop kbbug2.65 kbfix6.50.sp2

The information in this article applies to:

  • Microsoft Open Database Connectivity version 2.65
BUG #: 15705 (SQLBUG_65)

SYMPTOMS

When two or more threads share the same database connection (but different hstmts), a call to SQLExecDirect or SQLExecute fails, and one of the following errors occurs:

  • [Microsoft][ODBC SQL Server Driver][SQL Server] Received an unrecognized datatype 0 from TDS data stream
  • [Microsoft][ODBC SQL Server Driver]Unknown token received from SQL Server
  • [Microsoft][ODBC SQL Server Driver]Protocol error in TDS stream

The error(s) received depends on which network library (TCP/IP sockets or named pipes) is being used.

WORKAROUND

To work around this problem, do one of the following:

  • Use a Critical Section object around SQLExecDirect or SQLExecute.
  • Use a different connection for each thread, rather than sharing the same connection.
  • Add a Sleep function for about 1,000 to 5,000 milliseconds before SQLExecDirect or SQLExecute.

STATUS

Microsoft has confirmed this to be a problem in Microsoft SQL Server ODBC Driver version 2.65. This problem has been corrected in U.S. Service Pack 2 for Microsoft SQL Server version 6.5. For more information, contact your primary support provider.

Additional reference words: 2.65 MFC mfcdatabase Classes RDO Visual Basic
KBCategory: kbusage kbinterop kbbug2.65 kbfix6.50.sp2
KBSubcategory:
Keywords : kbbug2.65 kbfix6.50.sp2 kbinterop kbusage
Version : 2.65
Platform : WINDOWS
Solution Type : kbfix

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Last reviewed: October 29, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.