FIX: TDS Errors in a Multithreaded ODBC Application (154295)


The information in this article applies to:

  • Microsoft Open Database Connectivity
This article was previously published under Q154295
2.65
WINDOWS
kbusage kbinterop kbbug2.65 kbfix6.50.sp2
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.
Modification Type:MajorLast Reviewed:12/2/2002
Keywords:kbbug KB154295 kbAudDeveloper
©2002 Microsoft Corporation. All rights reserved.