FreeTDS Development Group

[Craig Davison <cd AT securityfocus.com>]

Hi again,

Is it possible to have two queries executing at once with the freetds ODBC 
driver? I've made a small test program that attempts this and it does not 
seem to work. (Change "user", "password" and "mydb" in main() to 
appropriate values to run)

The program is attached. It creates a statement handle and selects from 
the master..sysusers table. For each row returned, it performs another 
query. (Note that the program doesn't do anything useful at all, but the 
code should be legal).

The "inner" SQLExecDirect returns -1 and SQLGetDiagRec provides no 
further details. I'm using 0.61rc1 on a RedHat 8 (x86) client, with an MS 
SQL Server 2000 server. My ODBC driver manager is UnixODBC 2.2.2.

It could be that I've got some major oversight happening, as I'm still new 
to ODBC, but I can't seem to figure out why this isn't working.

Thanks!

-- 
Craig Davison
Symantec Corporation
+1 (403) 213-3939 ext. 228
#include <stdio.h>
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>


int CheckSQLHandle (SQLSMALLINT SQLHandleType, SQLHSTMT hStmt, long erg, 
const char *pDesc)
{
        SQLINTEGER SQLerr;
        SQLSMALLINT SQLmsglen;
        char pStatus[10], pMsg[101];
        long erg2;

        if (erg != SQL_SUCCESS && erg != SQL_SUCCESS_WITH_INFO)
        {
                fprintf(stderr, "Error %s %ld\n", pDesc, erg);
                erg2 = SQLGetDiagRec(SQLHandleType, hStmt,1,
                        pStatus,&SQLerr,pMsg,100,&SQLmsglen);
                if (erg2 == SQL_SUCCESS || erg == SQL_SUCCESS_WITH_INFO)
                {
                        fprintf(stderr, "%s (%d)\n",pMsg,(int)SQLerr);
                }
                return -1;
        }
        return 0;
}

int TryStuff (SQLHDBC hOdbc)
{
        SQLHSTMT hStmt;
        SQLINTEGER SQLerr, SQLid;
        long erg;

        SQLAllocHandle(SQL_HANDLE_STMT, hOdbc, &hStmt);
        SQLBindCol(hStmt, 1, SQL_C_SLONG, &SQLid, sizeof(SQLINTEGER), 
&SQLerr);
        
        erg = SQLExecDirect(hStmt, "SELECT uid FROM master..sysusers", 
SQL_NTS);
        if (CheckSQLHandle (SQL_HANDLE_STMT, hStmt, erg, "outer 
SQLExecDirect"))
        {
                SQLFreeHandle(SQL_HANDLE_STMT, &hStmt);
                return -1;
        }
        erg = SQLFetch(hStmt);
        while(erg != SQL_NO_DATA && erg != SQL_ERROR)
        {
                SQLHSTMT hAddrStmt;
                SQLINTEGER SQLaddress;
                char pQuery[501];
                long erg2;

                SQLAllocHandle(SQL_HANDLE_STMT, hOdbc, &hAddrStmt);
                SQLBindCol(hAddrStmt, 1, SQL_C_SLONG, &SQLaddress, 
sizeof(SQLINTEGER), &SQLerr);

                sprintf (pQuery, "SELECT uid FROM master..sysusers where 
uid=1234");
                fprintf (stderr, "%s\n", pQuery);
                erg2 = SQLExecDirect(hAddrStmt, pQuery, SQL_NTS);
                if (CheckSQLHandle (SQL_HANDLE_STMT, hAddrStmt, erg2, "inner 
SQLExecDirect"))
                {
                        SQLFreeHandle(SQL_HANDLE_STMT, &hAddrStmt);
                        return -1;
                }
                erg2 = SQLFetch (hAddrStmt);
                while (erg2 != SQL_NO_DATA && erg2 != SQL_ERROR)
                {
                        erg2 = SQLFetch (hAddrStmt);
                }
                if (erg2 == SQL_ERROR && CheckSQLHandle (SQL_HANDLE_STMT, 
hAddrStmt, erg2, "inner SQLFetch"))
                {
                        SQLFreeStmt (hAddrStmt, SQL_CLOSE);
                        SQLFreeHandle(SQL_HANDLE_STMT, &hAddrStmt);
                        return -1;
                }
                SQLFreeStmt (hAddrStmt, SQL_CLOSE);

                erg = SQLFetch(hStmt);  
        }
        if (erg == SQL_ERROR && CheckSQLHandle (SQL_HANDLE_STMT, hStmt, erg, 
"outer SQLFetch"))
        {
                SQLFreeStmt (hStmt, SQL_CLOSE);
                SQLFreeHandle(SQL_HANDLE_STMT, &hStmt);
                return -1;
        }
        SQLFreeStmt(hStmt, SQL_CLOSE);
        SQLFreeHandle(SQL_HANDLE_STMT, &hStmt);

        return 0;
}

int main (int argc, char **argv)
{
        SQLHENV hEnv;
        SQLHDBC hOdbc;
        long erg;
        int err;

        SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hEnv);
        SQLSetEnvAttr(hEnv, SQL_ATTR_ODBC_VERSION, (void*)SQL_OV_ODBC3, 0);
        SQLAllocHandle(SQL_HANDLE_DBC, hEnv, &hOdbc);

        /* connect to the database */
        erg = SQLConnect(hOdbc, (SQLCHAR*) "mydb", SQL_NTS,
                        (SQLCHAR*) "user", SQL_NTS,
                        (SQLCHAR*) "password", SQL_NTS);
        if (CheckSQLHandle (SQL_HANDLE_DBC, hOdbc, erg, "Database Connect"))
        {
                SQLFreeHandle(SQL_HANDLE_DBC, &hOdbc);
                SQLFreeHandle(SQL_HANDLE_ENV, &hEnv);
                return 0;
        }

        err = TryStuff (hOdbc);
        if (err < 0)
        {
                SQLDisconnect(hOdbc);
                SQLFreeHandle(SQL_HANDLE_DBC, &hOdbc);
                SQLFreeHandle(SQL_HANDLE_ENV, &hEnv);
                printf ("TryStuff returned %d\n", err);
                return 0;
        }

        SQLDisconnect(hOdbc);
        SQLFreeHandle(SQL_HANDLE_DBC, &hOdbc);
        SQLFreeHandle(SQL_HANDLE_ENV, &hEnv);

        return 0;
}