使用ADO如何调用数据库中的过程？

Question

// SQL Server, stored procedure , Command , Recordset, input parameter, output parameter, returned recordset from stored procedure
//execute stored procedure , get returned value, output value, and returned recordset.
#include "stdafx.h"
#import "C:\PROGRA~1\COMMON~1\System\ado\msado15.dll" rename( "EOF", "adoEOF" )
  struct InitOle
  {
    InitOle()  { ::CoInitialize(NULL); }
    ~InitOle() { ::CoUninitialize();  }
  } _init_InitOle_;
void PrintProviderError(ADODB::_ConnectionPtr pConnection);int main(int argc, char* argv[])
{
        printf("Create a adParamReturnValue for Command object to get return value of stored procedure\n");
        printf("Reference :MSDN---Append and CreateParameter Methods Example (VC++)\n");
        ADODB::_ConnectionPtr  Conn1;
        ADODB::_CommandPtr    Cmd1;
        ADODB::_RecordsetPtr  Rs1;
        ADODB::_ParameterPtr  retParam= NULL;
        ADODB::_ParameterPtr inParam=NULL;
        ADODB::_ParameterPtr outParam=NULL;
        _variant_t  vtEmpty (DISP_E_PARAMNOTFOUND, VT_ERROR);
        _variant_t  vtEmpty2 (DISP_E_PARAMNOTFOUND, VT_ERROR);
        _bstr_t    bstrConnect( L"driver={sql server};server=Cell;Database=zhg;UID=sa;PWD=;" );
        // the following stored procedure return 12345 int value
        _bstr_t    bstrCreate ( L"create proc sp_AdoTest( @OutParam int OUTPUT,@InParam int ) "
                L"as "
                L"select @OutParam = @InParam + 10 "
                L"select * from Table1"
                L"return 12345" );
        _bstr_t    bstrSP(L"sp_Adotest" );
        try
        {
                _bstr_t bstrEmpty;
                Conn1.CreateInstance( __uuidof( ADODB::Connection ) );
                Cmd1.CreateInstance( __uuidof( ADODB::Command ) );
                Rs1.CreateInstance(__uuidof(ADODB::Recordset));
                // Establish connection.
                Conn1->ConnectionString = bstrConnect;
                Conn1->Open( bstrConnect, bstrEmpty, bstrEmpty, -1 );
                // Open recordset.
                Cmd1->ActiveConnection = Conn1;
                Cmd1->CommandText      = bstrSP;
                Cmd1->CommandType      = ADODB::adCmdStoredProc;
                retParam=Cmd1->CreateParameter(_bstr_t("Return"),ADODB::adInteger,ADODB::adParamReturnValue,sizeof(int));
                Cmd1->Parameters->Append(retParam);
                outParam = Cmd1->CreateParameter(_bstr_t("OutParam"),ADODB::adInteger,ADODB::adParamOutput,sizeof(int));
                Cmd1->Parameters->Append(outParam);
                inParam = Cmd1->CreateParameter(_bstr_t("InParam"),ADODB::adInteger,ADODB::adParamInput,sizeof(int),_variant_t( (long) 10 ));
                inParam->Value=_variant_t( (long) 10 );
                Cmd1->Parameters->Append(inParam);
                Cmd1->Parameters->Refresh();
                Cmd1->Parameters->Item[ _variant_t( _bstr_t("@InParam") ) ]->Value =_variant_t( (long) 11 );
                Rs1->put_CursorLocation(ADODB::adUseClient);
                Rs1->Open((_variant_t((IDispatch *) Cmd1)),vtEmpty,ADODB::adOpenStatic,
                        ADODB::adLockReadOnly, -1);
                // Get return value of the stored procedure.adCmdUnknown
                TCHAR tcbuf[1024];
                long retvalue=Cmd1->Parameters->Item[(short)0]->Value;
                long p2=Cmd1->Parameters->Item[(short)1]->Value;
                long p3=Cmd1->Parameters->Item[(short)2]->Value;
                int recordcount=0;
                if(Rs1->State==ADODB::adStateClosed)
                        MessageBox(NULL,"no recordset is returned from the stored procedure","Information",MB_OK);
                else
                        recordcount = Rs1->GetRecordCount();
                wsprintf(tcbuf,"retvalue of the stored procedure:%d,input value:%d,output value:%d,record count :%d",retvalue,p2,p3,recordcount);
                MessageBox(NULL,tcbuf,"Output",MB_OK);
        }
  catch(_com_error &e)
  {
      _bstr_t bstrSource(e.Source());
      _bstr_t bstrDescription(e.Description());
      printf("\nCOM error occurred, Source : %s \n Description : %s \n",(LPCSTR)bstrSource,(LPCSTR)bstrDescription);
    PrintProviderError(Conn1);
  }
        return 0;
}
VOID PrintProviderError(ADODB::_ConnectionPtr pConnection)
{
  // Print Provider Errors from Connection object.
  // pErr is a record object in the Connection's Error collection.
        ADODB::ErrorPtr  pErr = NULL;
  long      nCount = 0;
  long      i = 0;  if( (pConnection->Errors->Count) > 0)
  {
      nCount = pConnection->Errors->Count;
      // Collection ranges from 0 to nCount -1.
      for(i = 0; i < nCount; i++)
      {
        pErr = pConnection->Errors->GetItem(i);
        printf("\n\t Error number: %x\t%s", pErr->Number, (LPCSTR)pErr->Description);
      }
  }
}