DOCUMENT:Q154295  25-MAR-2000  [odbc]
TITLE   :FIX: TDS Errors in a Multithreaded ODBC Application
PRODUCT :Open Database Connectivity (ODBC)
PROD/VER:WINDOWS:2.65
OPER/SYS:
KEYWORDS:

======================================================================
2.65

WINDOWS

kbusage kbinterop kbbug2.65 kbfix6.50.sp2

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The information in this article applies to:

 - Microsoft Open Database Connectivity, version 2.65 
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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

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

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