ActiveCommand Property Example (VC++)

This example demonstrates the ActiveCommand property.

A subroutine is given a Recordset object whose ActiveCommand property is used to display the command text and parameter that created the Recordset.

// BeginActiveCommandCpp
#import "C:\Program Files\Common Files\System\ADO\msado15.dll" \
    no_namespace rename("EOF", "EndOfFile")


#include <ole2.h>
#include <stdio.h>
#include <conio.h>
#include "ActiveCommandX.h"

// Function declarations
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);};
void ActiveCommandX(void);
void ActiveCommandXprint(_RecordsetPtr   pRst);
void PrintProviderError(_ConnectionPtr pConnection);
void PrintComError(_com_error &e);


//////////////////////////////////////////////////////////
//                                                      //
//        Main Function                                 //
//                                                      //
//////////////////////////////////////////////////////////

void main()
{
   if(FAILED(::CoInitialize(NULL)))
      return;
   
    ActiveCommandX();
    
    ::CoUninitialize();
}

//////////////////////////////////////////////////////////
//                                                      //
//            ActiveCommandX Function                   //
//                                                      //
//////////////////////////////////////////////////////////

void ActiveCommandX(void) 
{

   HRESULT   hr = S_OK;

   // Define ADO object pointers.
    // Initialize pointers on define.
    // These are in the ADODB::  namespace.
   _ConnectionPtr  pConnection      = NULL;
   _CommandPtr    pCmd      = NULL;
   _RecordsetPtr  pRstAuthors    = NULL;
   
   //Definitions of other variables
   _bstr_t strCnn("Provider=SQLOLEDB;Data Source=MyServer;Initial Catalog=pubs;User Id=sa;Password=;");
   _bstr_t      strPrompt;
   _bstr_t      strName;
   CHAR strcharName[50];
   

   try
   {
      // Open connection.
      TESTHR(pConnection.CreateInstance(__uuidof(Connection)));
   
      TESTHR(pRstAuthors.CreateInstance(__uuidof(Recordset)));

      TESTHR(pCmd.CreateInstance(__uuidof(Command)));

      printf ("ActiveCommandX Example\n\n");
      strPrompt = "Enter an author's name (e.g., Ringer): ";
      printf(strPrompt);
      gets(strcharName);
      char *tempStr = strtok(strcharName, " \t");
      strName = tempStr;
      
      pCmd->CommandText = "SELECT * FROM authors WHERE au_lname = ?";
      pCmd->Parameters->Append(pCmd->CreateParameter("LastName", adChar, adParamInput, 20, strName));

      pConnection->Open (strCnn, "", "", adConnectUnspecified);

      pCmd->PutActiveConnection(_variant_t((IDispatch*)pConnection));

      pRstAuthors = pCmd->Execute(NULL,NULL,adCmdText);

      ActiveCommandXprint(pRstAuthors);

      // Clean up objects before exit.
      pRstAuthors->Close();
      pConnection->Close();

   }   // End Try statement.

   catch(_com_error &e)
   {
      // Notify the user of errors if any.
      // Pass a connection pointer accessed from the Recordset.
      PrintProviderError(pConnection);
      PrintComError(e);  
   }

}


//////////////////////////////////////////////////////////
//                                                      //
//              ActiveCommandXprint Function            //
//                                                      //
//////////////////////////////////////////////////////////

void ActiveCommandXprint(_RecordsetPtr   pRst = NULL)
{
   // Varible Declaraion & initialization
   IADORecordBinding   *picRs  = NULL;  //Interface Pointer declared. 
   CAuthorsRs autrs;           //C++ class object
   HRESULT hr;
   _bstr_t strName;
   
   //Open an IADORecordBinding interface pointer which 
   //we'll use for Binding Recordset to a class    
   TESTHR(pRst->QueryInterface(__uuidof(IADORecordBinding),(LPVOID*)&picRs));
   
   //Bind the Recordset to a C++ Class here    
   TESTHR(picRs->BindToRecordset(&autrs));
   
   strName = ((_CommandPtr)pRst->GetActiveCommand())->GetParameters()->GetItem("LastName")->Value;
   printf("Command text = '%s'\n", (LPCSTR)((_CommandPtr)pRst->GetActiveCommand())->CommandText);
   printf("Parameter = '%s'\n", (LPCSTR)strName);

   if (pRst->BOF)
      printf("Name = '%s'not found.", (LPCSTR)strName);
   else
   {
      printf ("Name = '%s  %s' author ID = '%s'",
         autrs.lau_fnameStatus == adFldOK ? autrs.m_au_fname : "<NULL>",
         autrs.lau_lnameStatus == adFldOK ? autrs.m_au_lname : "<NULL>",
         autrs.lau_idStatus == adFldOK ? autrs.m_au_id : "<NULL>");
   }

   //Release IADORecordset Interface    
   if (picRs)
   picRs->Release();

}

//////////////////////////////////////////////////////////
//                                                      //
//        PrintProviderError Function                   //
//                                                      //
//////////////////////////////////////////////////////////

void PrintProviderError(_ConnectionPtr pConnection)
{
   // Print Provider Errors from Connection object.
   // pErr is a record object in the Connection's Error collection.
   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("\t Error number: %x\t%s\n", pErr->Number, (LPCSTR)pErr->Description);
      }
   }
}

//////////////////////////////////////////////////////////
//                                                      //
//       PrintComError Function                         //
//                                                      //
//////////////////////////////////////////////////////////

void PrintComError(_com_error &e)
{
   _bstr_t bstrSource(e.Source());
   _bstr_t bstrDescription(e.Description());
   
   // Print Com errors.  
   printf("Error\n");
   printf("\tCode = %08lx\n", e.Error());
   printf("\tCode meaning = %s\n", e.ErrorMessage());
   printf("\tSource = %s\n", (LPCSTR) bstrSource);
   printf("\tDescription = %s\n", (LPCSTR) bstrDescription);
   
}
// EndActiveCommandCpp

ActiveCommandX.h

// BeginActiveConnectionH
#include "icrsint.h"


//This Class extracts  fname,lastname    

class CEmployeeRs : public CADORecordBinding
{
BEGIN_ADO_BINDING(CEmployeeRs)
    
   //Column au_id is the 1st field in the recordset   
   ADO_VARIABLE_LENGTH_ENTRY2(1, adVarChar, m_szau_id, 
         sizeof(m_szau_id), lau_idStatus, TRUE)

    ADO_VARIABLE_LENGTH_ENTRY2(2, adVarChar, m_szau_lname, 
         sizeof(m_szau_lname), lau_lnameStatus, TRUE)

   ADO_VARIABLE_LENGTH_ENTRY2(3, adVarChar, m_szau_fname, 
         sizeof(m_szau_fname), lau_fnameStatus, TRUE)
   
END_ADO_BINDING()

public:

   CHAR m_szau_id[20];
   ULONG lau_idStatus;

   CHAR m_szau_fname[40];
   ULONG lau_fnameStatus;
   
   CHAR   m_szau_lname[40];
   ULONG  lau_lnameStatus;

};
// EndActiveConnectionH

ActiveCommand Property Example (VC++)

See Also