activecommandx.cpp

visual c++ 很全的ado的sample

#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, "", "", NULL);

		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);
   
}