Do Oracle ODBC drivers support asynchronous mode? If so, which ones and how?

From: Pavel Sustr <Pavel.Sustr_at_cristal.cz>
Date: 2000/04/03
Message-ID: <8c9f68$2cm$1@ns.felk.cvut.cz>#1/1

Hello,

Problem:

---

We have a MFC application running on Windows 2000 that uses Oracle ODBC driver(s). How can we cancel an SQL query?

What we've tried:

---

We've tried to use two ODBC drivers, Oracle73 driver version 1.15.03.01 (as displayed in the ODBC Data Source Administrator) and Oracle ODBC driver version 8.01.05.00. We've tried using asynchronous mode:

// =====================================================

// 1) Check whether the driver supports asynchronous mode

// =====================================================

retcode = SQLGetInfo(hdbc1, SQL_ASYNC_MODE, &nAsync, sizeof(nAsync), &nResult);

• Oracle73 returned: Information type out of range
• Oracle81 returned: Assynchronous mode is not supported

// =====================================================

// 2) Never mind (explained later). Specify that hstmt1 is to be executed asynchronously.

// =====================================================

retcode = SQLSetStmtAttr(hstmt1, SQL_ATTR_ASYNC_ENABLE,(void*) SQL_ASYNC_ENABLE_ON, SQL_NTS);

• Oracle73 returned: no error (!)
• Oracle81 returned: SQLAllocHandle(hstmt1) Failed

// =====================================================

// 3) Try to execute the command

// =====================================================

while ((retcode = SQLExecDirect(hstmt1, (unsigned char*)(LPCSTR)sqlCommand, SQL_NTS)) == SQL_STILL_EXECUTING)
{
...
SQLCancel(hstmt1);
...
}

• Oracle73 returned: no error (!)
• Oracle81 fails during the execution of 2), never reaches this part of the code

It seems to me that Oracle73 driver supports asynchronous mode (despite the fact that whenever asked, using SQLGetInfo(...SQL_ASYNC_MODE...), it replies NO) but Oracle 8i doesn't! How come? If that's the case, will future Oracle ODBC drivers support it?

Any comments appreciated. Thank you in advance.

Pavel Sustr
CRISTAL Software CZ Received on Mon Apr 03 2000 - 00:00:00 CDT