Работа с БД: с чего начать

                pConnection.CreateInstance(__uuidof(ADODB::Connection));
                pConnection->Open((L"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\\Parik.mdb;"), _bstr_t(""), _bstr_t(""), 0);
                string a;
                if (pConnection->State == 1) a = "Соединение установлено";
                else a = "Соединение не установлено";
                cout << "Состояние соединения: " << a << "\n";
                    pCommand.CreateInstance(__uuidof(ADODB::Command));
                    pCommand->ActiveConnection = pConnection;
                    pCommand->CommandText = _bstr_t("Select Firm From Enterprise");
                    pCommand->CommandType = ADODB::CommandTypeEnum(1);
                    _variant_t  vtRowsAffected;
                    _variant_t  vtMissing;
                    ADODB::_CommandPtr Comm;
                    Comm = pCommand->Execute(&vtRowsAffected, &vtMissing, ADODB::adCmdText);

Comm = pCommand->Execute(nullptr, nullptr, ADODB::adCmdText);

#pragma warning(disable : 4996)
#include <string>
#include <iostream>
#import "c:/Program Files/Common Files/System/ADO/msado15.dll" rename("EOF","AdoNSEOF")
using namespace std;
using namespace ADODB;//необходимо для макросов AD_BINDING
inline void TESTHR(HRESULT x)
{
    if FAILED(x) _com_issue_error(x);
};
void OpenX();
void PrintProviderError(_ConnectionPtr pConnection);
void PrintComError(_com_error& e);
 
int main1()
{
    if (FAILED(::CoInitialize(NULL)))
        return -1;
 
    OpenX();
    ::CoUninitialize();
}
 
void OpenX()
{
    // Define ADO object pointers.  Initialize pointers on define.  
    // These are in the ADODB:: namespace  
    _RecordsetPtr pRSet = NULL;
    _ConnectionPtr pConnection = NULL;
 
    setlocale(LC_ALL, "Russian");
    _bstr_t strCnn("Provider='Microsoft.ACE.OLEDB.16.0'; Data Source='D:\\Parik.accdb'; ''; ''; 0");
try
    {
        // открываем соединение и набор записей  
        TESTHR(pConnection.CreateInstance(__uuidof(Connection)));
        pConnection->Open(strCnn, "", "", adConnectUnspecified);
        string a;
        if (pConnection->State == 1) a = "Connection enabled";
        else a = "Connection don't enabled";
        printf ("Connection status: ",  a );
        TESTHR(pRSet.CreateInstance(__uuidof(Recordset)));
        pRSet->Open("Select * From Enterprise", _variant_t((IDispatch*)pConnection, true),
            adOpenKeyset, adLockOptimistic, adCmdText);
 
        if (pRSet->State == 1) a = "Recordset enabled";
        else a = "Recordset don't enabled";
        cout << "Recordset status: " << a << "\n";
 
        FieldsPtr pFields;
        FieldPtr pField;
        pFields = pRSet->Fields;
        int nNumFields = pRSet->Fields->Count;
        int nNumRows = pRSet->RecordCount;
        cout << "Количество записей (строк) в RecordSet: " << nNumRows << "\n";
        char* pName;
        int const n = 10;
        char const m = 20;
        char* Arr[n][m];
        int i;
        int k;
        //int a = 0;
        for (i = 0; i < nNumFields; i++)
        {
            pName = new char[pRSet->Fields->Item[(HRESULT)i]->Name.length()];
            strcpy(pName, (LPCSTR)pRSet->Fields->Item[(HRESULT)i]->Name);
            Arr[i][0] = pName;
            fprintf(stderr, "%s                        ", Arr[i][0]);
        }
        cout << "" << "\n";
        pRSet->AbsolutePosition; //устанавливаем курсор в начало
 
        while (!pRSet->AdoNSEOF)
        {
            for (i = 0, k = 0; i < nNumFields; i++, k++)
            {
                cout << _bstr_t(pRSet->Fields->Item[Arr[k][0]]->Value) << "                           ";
                if (k == nNumFields - 1) cout << "\n ";
 
            }
            pRSet->MoveNext();
        }
 
}
    catch (_com_error& e)
    {
        // Display errors, if any. Pass a connection pointer accessed from the Connection.  
        PrintProviderError(pConnection);
        PrintComError(e);
    }
 
    // Clean up objects before exit.  
    if (pRSet)
        if (pRSet->State == adStateOpen)
            pRSet->Close();
    if (pConnection)
        if (pConnection->State == adStateOpen)
            pConnection->Close();
 
    system("PAUSE");
}
 
void PrintProviderError(_ConnectionPtr pConnection)
{
    // Print Provider Errors from Connection object.  
    // pErr is a record object in the Connection's Error collection.  
    ErrorPtr pErr = NULL;
 
    if ((pConnection->Errors->Count) > 0)
    {
        long nCount = pConnection->Errors->Count;
        // Collection ranges from 0 to nCount -1.  
        for (long i = 0; i < nCount; i++)
        {
            pErr = pConnection->Errors->GetItem(i);
            //printf("\t Error number: %x\t%s", pErr->Number, pErr->Description);
            cout << "Error number: " << (pErr->Number, pErr->Description) << "\n";
        }
    }
}
 
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());
    cout << "Code meaning " << e.ErrorMessage() << "\n";
    printf("\tSource = %s\n", (LPCSTR)bstrSource);
    printf("\tDescription = %s\n", (LPCSTR)bstrDescription);
}

pRSet->Close();
    pConnection->Close();