BUG: SQL_PRESERVE_CURSORS Fails on Reuse of a Connection Handle

• Microsoft SQL Server version 6.5
• Microsoft Open Database Connectivity version 3.0

SYMPTOMS

If you reuse a previously used connection handle and attempt to preserve cursors over transaction boundaries (that is, if the SQL Server driver connect option SQL_PRESERVE_CURSORS is used), the following error occurs:

   [Microsoft][ODBC Driver Manager] Function sequence error

WORKAROUND

To work around this problem, do not reuse connection handles if you need to preserve cursors. Instead, close the handle and reopen a new one for preserve cursor operations.

STATUS

Microsoft has confirmed this to be a problem in SQL Server version 6.5 and Open Database Connectivity version 3.0. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following script, used with ODBC Test (Odbcte32.exe) demonstrates the problem:

   1)   Full Connect:  (connect to Pubs).
   2)   SQLDisconnect:
   3)   SQLSetConnectOption:
         fOption=Conn: SQL_ODBC_CURSORS=110,
         vParam=SQL_CUR_USE_DRIVER=2
   4)   SQLDriverConnect: (reconnect to Pubs)
   5)   SQLSetConnectOption:
         fOption=Conn: SQL_AUTOCOMMIT=102,
         vParam=SQL_AUTOCOMMIT_OFF=0
   6)   SQLAllocStmt:
   7)   SQLSetStmtOption:
         fOption=SQL_CURSOR_TYPE=6,
         vParam=SQL_CURSOR_STATIC=3
   8)   SQLSetConnectOption:
         fOption=1204 (#def value for SQL_PRESERVE_CURSORS)
         vParam=1 (#def value for SQL_PC_ON)
   9)   SQLPrepare:
         select emp_id, fname from employee where job_id = 13
   10)   SQLExecute:
   11)   SQLTransact:
   12)   Bind Col All:
   13)   SQLSetStmtOption:
         fOption=SQL_ROWSET_SIZE=9,
         vParam=20,
   14)   SQLExtendedFetch:
         fFetchType=SQL_FETCH_NEXT=1
         irow=0, pcrow=VALID, rgfRowStatus=VALID
      Return:   SQL_ERROR=-1
      szSqlState = "S1010", *pfNativeError = 0, *pcbErrorMsg = 56
      szErrorMsg="[Microsoft][ODBC Driver Manager] Function sequence error"

• Do not disconnect.

  -or-

• Free the connection handle and allocate a new one.