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Q154295: FIX: TDS Errors in a Multithreaded ODBC Application

Article: Q154295
Product(s): Open Database Connectivity (ODBC)
Version(s): WINDOWS:2.65
Operating System(s): 
Keyword(s): 
Last Modified: 25-MAR-2000

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 query words: MFC mfcdatabase Classes RDO Visual Basic

======================================================================
Keywords          :  
Technology        : kbAudDeveloper kbODBCSearch
Version           : WINDOWS:2.65
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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