My Database ODBC Driver is behaving strange with an application that uses
windows methods
_bstr_t getInvs;
getInvs = "select * from temp";
m_GetInvsCommand.CreateInstance(__uuidof(Command)) ;
m_GetInvsCommand->ActiveConnection = m_DBHandler->mConnection ;

SQLDriverConnect is already called in the begining of the application.These calls are done before SQLPrepare .

Dont know why with m_GetInvsCommand->ActiveConnection = m_DBHandler->mConnection ;
SQLDriverconnect is called again.New connection handle is also allocated...
kind off confused
Anyone seen this error before?

Maybe I'm confused, but someone (probably you) has to write all of the C code that uses an ODBC driver. Code doesn't materialize out of thin air just because you use the driver.

Can you explain what you are asking more clearly?

-PatP

Hi pat ,
Thanks for your response. I have written a small application that would be connected to a ODBC Driver OpenConnection ADO method would call SQLDriverConnect.

Later in BOOL PrepareMPSUpdate1() function when

m_GetInvsCommand1.CreateInstance(__uuidof(Command) );
m_GetInvsCommand1->ActiveConnection = m_DBHandler->mConnection ;

is called SQLDriverConnect is called again.Wondering why this kind of behaviour.This is not reproducible in oracle.
But in my ODBC driver this is the behavior,hope this can give some idea...

#include "stdafx.h"
#include "windows.h"
#include "DBHandler.h"
#include "conio.h"
#include <sys/timeb.h>

typedef struct MKIPrice
{
long MKINo;
char type[4];
char Exch[4];
double YCP;
double LTP;
short Level;
double InitalTrigValLow;
double InitalTrigValHig;
double IncrTrigpriceLow;
double IncrTrigpriceHig;
char StockGroup;
bool MkiFlag;

}MKIPrice;

static bool gflag = false;
typedef char TUserCode[13];
DWORD m_dwThreadID;
HANDLE m_hThread,m_hTimerQueue,m_hTimer;
CDBHandler *m_DBHandler;
CTracer *m_pTracer;

BOOL PrepareMPSUpdate1();
BOOL PrepareMPSUpdate();
BOOL UpdateMPS();
void GetNSOdbc_time_stamp(char *timedate);

_CommandPtr m_MkiTrueCommand,m_MkiFalseCommand,m_SelectMkiComm and;
_CommandPtr m_GetInvsCommand1,m_GetInvsCommand,m_UpdateCommand ,m_InsertCommand;
_ParameterPtr m_PctParam;
_ParameterPtr m_Qty,m_Qty1;
_ParameterPtr m_MkiNum,m_MkiNum1;
_ParameterPtr m_MkiTrueParam,m_MkiFalseParam,m_MkiSelectParam;
_ParameterPtr m_DispUpdtParam,m_CurrUpdtTSParam,m_UsrCodeParam,m _CurrUpdtDateParam ,m_MTMPdtParam ;
_ParameterPtr m_PartIDParam,m_DispParam,m_CurrTSParam,m_PricePar am,m_CurrDateParam,m_ExchParam,m_PdtParam,m_insMki Param,m_DerviParam,m_LTPParam,m_LevelParam,m_Proce ssParam;

int main(int argc, char* argv[])
{
long dwNoOfBackUps =1;
m_DBHandler = new CDBHandler();

//Calls SQLDriverConnect

m_DBHandler->CreateConnection();
m_DBHandler->OpenConnection();

PrepareMPSUpdate();
PrepareMPSUpdate1();
char lStartTime[50];
char lEndTime[50];

GetNonStopOdbc_time_stamp(lStartTime);
printf("Start Timesatmp %s \n", lStartTime);

printf("before for loop\n");
for (int i = 0; i < 100; i++)
{
UpdateMPS();
getch();
}
GetNonStopOdbc_time_stamp(lEndTime);
printf("Start Timesatmp %s \n", lEndTime);

HANDLE hEvent;
hEvent = CreateEvent( NULL, FALSE, FALSE, NULL);
ASSERT(hEvent);
printf("before wait for single object\n");
WaitForSingleObject(hEvent,INFINITE);
printf("after wait for single object");
return 0;
}


void GetNSOdbc_time_stamp(char *timedate)
{
struct tm *today;
time_t ltime;
char time_string[40];
memset(time_string,'\0',40);
struct _timeb timebuffer;
char *timeline;

_ftime(&timebuffer);
timeline = ctime(& ( timebuffer.time ));

time( &ltime );

today = localtime( &ltime );

strftime(time_string, sizeof (time_string), "%Y-%m-%d %H:%M:%S", today);
sprintf(timedate,"%s.%ld",time_string,timebuffer.m illitm);

}


BOOL PrepareMPSUpdate()
{
_bstr_t getInvs;
getInvs = "update m_p_s set mps_total_traded_qty = ? where mps_mkt_instr_no = ?";
m_GetInvsCommand.CreateInstance(__uuidof(Connectio n));
m_GetInvsCommand->ActiveConnection = m_DBHandler->mConnection ;
m_GetInvsCommand->CommandText = getInvs;
m_GetInvsCommand->PutPrepared(true);
m_Qty = m_GetInvsCommand->CreateParameter( "",adChar,adParamInput,10);
m_MkiNum = m_GetInvsCommand->CreateParameter( "",adChar,adParamInput,10);;
m_GetInvsCommand->Parameters->Append( m_Qty);
m_GetInvsCommand->Parameters->Append( m_MkiNum);
return TRUE;
}

BOOL PrepareMPSUpdate1()
{
_bstr_t getInvs1;
getInvs1 = "update m_p_s set mps_t_trad_qty = ? where mps_mkt_instr_no = ?";
m_GetInvsCommand1.CreateInstance(__uuidof(Command) );
m_GetInvsCommand1->ActiveConnection = m_DBHandler->mConnection ;
m_GetInvsCommand1->CommandText = getInvs1;
m_GetInvsCommand1->PutPrepared(true);
m_Qty1 = m_GetInvsCommand1->CreateParameter( "",adChar,adParamInput,10);
m_MkiNum1 = m_GetInvsCommand1->CreateParameter( "",adChar,adParamInput,10);;
m_GetInvsCommand1->Parameters->Append( m_Qty1);
m_GetInvsCommand1->Parameters->Append( m_MkiNum1);
return TRUE;
}


BOOL UpdateMPS()
{
long lqyt,lmkino;
char lExeTime[50];

lqyt = 100;
lmkino = 22;
m_Qty->Value = _variant_t(lqyt);
m_MkiNum->Value = _variant_t(lmkino);
try
{
m_GetInvsCommand->Execute( NULL, NULL, adCmdText );
GetNonStopOdbc_time_stamp(lExeTime);
printf("Execute Successfull %s \n",lExeTime);
}
catch(_com_error &lError)
{
throw lError;
}
return true;
}

may be i should make my question it less complicated.22 views and no replies...

1 question on ADO's method pAdoCommand->putref_ActiveConnection
which has one argument the connection.Any chance that it should call for a connection again(Call SQLDriverConnect) ,Even if the object is a valid one..