ODBC connection

[cyq84]

Hi all,

May i know how to establish a ODBC connection to SQL sever 2005 via c++ and retrieve the data from the database at the console application? I had written the following codes:

try
{
CDatabase cdb;

CString sSQLStmt ="SELECT sequenceId FROM AuthEvents";
int bconnect;

CString str = "ODBC;DSN=EARTH;UID=sa;PWD=pass#word1;" ;

bconnect=cdb.Open(str);

if(!bconnect)
printf("failed");

else
printf("connection open successfully");



CRecordset rs(&cdb);
rs.m_strFilter =sSQLStmt;

rs.Open();


}


catch(_com_error )
{
printf("Error");
}


Currently, the program was able to open the connection successfuly but there is an error (runtime error) when it runs the line rs.Open().Could someone help me with this? Thanks

[guruplus]

How did you know it is connected or not?

use this class to connect dbms
I know it does not look nice, but it works, just change connection string, and
run sql

#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream.h>
#include <string>	
#define  ENGLISH_MAX 2500

#import "C:\Program Files\Common Files\System\ado\msado15.dll"  no_namespace   rename( "EOF", "adoEOF" )


class cReadText
{	
public:
	
	cReadText();
	cReadText(char* Filename);
	void ConnectionAdo();
	_RecordsetPtr GetRecordset(_bstr_t SQL);
	void RunCammand(_bstr_t SQL);
	~cReadText();

private:
_ConnectionPtr m_pConn;
_RecordsetPtr pRecordset;
_CommandPtr pCommand;
CString sCommand;
_bstr_t strSQL;
bool bConnected;
int done;
int englishmax;

	FILE* Filesourse;
	char* chFilename; 

};

#include "StdAfx.h"
#include <fstream>
#include "FileReader.h"

using namespace std;


cReadText::cReadText()
{
	CoInitialize(NULL);		
	bConnected = false;
	englishmax = 0;	
	
}

cReadText::cReadText(char* Filename)
{
	CoInitialize(NULL);	
	chFilename = Filename;
	bConnected = false;
	englishmax = 0;
	
	
}

void  cReadText::ConnectionAdo()  	
{
	bConnected = true;

	try	
	{
		HRESULT hr = m_pConn.CreateInstance (__uuidof (Connection));

		if (FAILED (hr))
		{
			AfxMessageBox ("Can't create intance of Connection");
		}
		if (FAILED (m_pConn->Open (_bstr_t("Provider=Microsoft.Jet.OLEDB.4.0;Data Source = EmailReminder.mdb;"),
					_bstr_t (""), _bstr_t (""), adModeUnknown)))
		{
			AfxMessageBox ("Can't open datasource");
		}		
	}
	catch( _com_error &e )
	{
		_bstr_t bstrSource(e.Source());
		_bstr_t bstrDescription(e.Description());
		TRACE( "Exception thrown for classes generated by #import" );
		TRACE( "\tCode = %08lx\n", e.Error());
		TRACE( "\tCode meaning = %s\n", e.ErrorMessage());
		TRACE( "\tSource = %s\n", (LPCTSTR) bstrSource);
		TRACE( "\tDescription = %s\n", (LPCTSTR) bstrDescription);
		AfxMessageBox ((LPCTSTR) bstrDescription);
		AfxMessageBox ((LPCTSTR) e.Source());
		

		bConnected = false;

	}
	catch (...)
	{
		bConnected = false;
	}
	

}

void cReadText::RunCammand(_bstr_t SQL)
{

	m_pConn->Execute(SQL,NULL,adExecuteNoRecords);
	
}

_RecordsetPtr cReadText::GetRecordset(_bstr_t SQL)
{
	
	pCommand.CreateInstance (__uuidof (Command));
	pCommand->ActiveConnection = m_pConn; 
	pCommand->CommandText = SQL;		
	pRecordset.CreateInstance (__uuidof (Recordset));
	pRecordset->CursorLocation = adUseClient;
	pRecordset->Open ( (IDispatch *) pCommand, vtMissing, adOpenStatic,adLockBatchOptimistic, adCmdUnknown);
	return pRecordset;

}

cReadText::~cReadText()
{
	 if (bConnected)
	 {
		 m_pConn->Close();
	 }
	CoUninitialize();

}

[cyq84]

Hi,

I had solved it. It is calling using ODBC. Thanks anyway.


CString sSQLStmt ="SELECT * FROM aaa";
int bconnect;

CString str = "ODBC;DSN=xxxxx;UID=sa;PWD=pass;" ;

bconnect=cdb.Open(str);
if(!bconnect)
printf("failed");

else
printf("connection open successfully\n");




CRecordset rs(&cdb);



CString varValue;

CDBVariant varValue1;

_bstr_t eventTime;


rs.Open( CRecordset::forwardOnly, sSQLStmt );


short nFields = rs.GetODBCFieldCount( );
while( !rs.IsEOF( ) )
{

rs.GetFieldValue( "[column name]", varValue);
eventTime = varValue;
printf("eventTime: %s\n\n", varValue);
rs.MoveNext( );

}

rs.Close( );