AddNew Method Example (VC++)

AddNew Method Example (VC++)

This example uses the AddNew method to create a new record with the specified name.

#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 "AddNewX.h"

//Function declaration
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);};
void AddNewX(void);
void PrintProviderError(_ConnectionPtr pConnection);

///////////////////////////////////////////////////////////
//                                                       //
//      Main Function                                    //
//                                                       //
///////////////////////////////////////////////////////////
void main()
{
    if(FAILED(::CoInitialize(NULL))) 
        return; 

    AddNewX();

    ::CoUninitialize();
}

///////////////////////////////////////////////////////////
//                                                       //
//      AddNewX Function                                 //
//                                                       //
///////////////////////////////////////////////////////////
void  AddNewX(void)
{
    // Define ADO object pointers.
    // Initialize pointers on define.
    _RecordsetPtr  pRstEmployees = NULL;
    _ConnectionPtr pConnection   = NULL;

    //Define Other variables
    IADORecordBinding   *picRs = NULL;  //Interface Pointer declared.
    CEmployeeRs emprs;                  //C++ class object   
    HRESULT hr = S_OK;

    _bstr_t strCnn("Provider=sqloledb;Data Source=srv;”
                “Initial Catalog=Pubs;User Id=sa;Password=;");
    _bstr_t strId;
    _bstr_t strMessage;

    try
    {
        //Open a connection
        TESTHR(pConnection.CreateInstance(__uuidof(Connection)));
        hr = pConnection->Open(strCnn,"","",NULL);

        //Open employee table. 
        TESTHR(pRstEmployees.CreateInstance(__uuidof(Recordset)));

        //You have to explicitly pass the Cursor type and LockType 
        //to the Recordset here.
        pRstEmployees->Open("employee",
            _variant_t((IDispatch *) pConnection,true),
            adOpenKeyset,adLockOptimistic,adCmdTable);

        //Open an IADORecordBinding interface pointer which we'll use 
        //for Binding Recordset to a class.
        TESTHR(pRstEmployees->QueryInterface(
                __uuidof(IADORecordBinding),(LPVOID*)&picRs));

        //Bind the Recordset to a C++ Class here
        TESTHR(picRs->BindToRecordset(&emprs)); 

        // Get data from the user.The employee id must be formatted as
        // first,middle and last initial,five numbers,then M or F to
        // signify the gender.For example,the employee id for 
        // Bill A. Sorensen would be "BAS55555M". 

        printf("Enter Employee Id: ");scanf("%s",emprs.m_sz_empid);
        strId = emprs.m_sz_empid;
        printf("Enter First Name: ");scanf("%s",emprs.m_sz_fname);
        printf("Enter Last Name:");scanf("%s",emprs.m_sz_lname);

        //Proceed if the user actually entered something  
        //for the id, the first and the last name. 

        if(strcmp(emprs.m_sz_empid,"") && 
           strcmp(emprs.m_sz_fname,"") && 
           strcmp(emprs.m_sz_lname,""))
        {
            //This adds a new record to the table
            //if (FAILED(hr = picRs->AddNew(&emprs)))
            //_com_issue_error(hr);
            TESTHR(picRs->AddNew(&emprs));

            //Show the newly added data
            printf("New Record: %s  %s  %s \n",
                emprs.lemp_empidStatus == adFldOK ? 
                emprs.m_sz_empid : "<NULL>",
                emprs.lemp_fnameStatus == adFldOK ? 
                emprs.m_sz_fname : "<NULL>",
                emprs.lemp_lnameStatus == adFldOK ? 
                emprs.m_sz_lname : "<NULL>");
        }
        else
            printf("Please enter an employee id, first name “
                “and last name.\n");

        //Delete the new record because this is a demonstration. 
        pConnection->Execute("DELETE FROM EMPLOYEE WHERE emp_id ="
            "'" + strId + "'",NULL,adCmdText);

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

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

    catch(_com_error &e)
    {
        // Notify the user of errors if any.
        _variant_t vtConnect = pRstEmployees->GetActiveConnection();

        // GetActiveConnection returns connect string if connection
        // is not open, else returns Connection object.
        switch(vtConnect.vt)
        {
            case VT_BSTR:
                printf("Error:\n");
                printf("Code = %08lx\n", e.Error());
                printf("Message = %s\n", e.ErrorMessage());
                printf("Source = %s\n", (LPCSTR) e.Source());
                printf("Description = %s\n", (LPCSTR) e.Description());
                break;
            case VT_DISPATCH:
                PrintProviderError(vtConnect);
                break;
            default:
                printf("Errors occured.");
                break;
        }
    }
}

///////////////////////////////////////////////////////////
//                                                       //
//      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("\n\t Error number: %x\t%s", 
                pErr->Number, (LPCSTR)pErr->Description);
        }
    }
}

AddNewX.h:

#include "icrsint.h"

//This Class extracts empid, fname and lastname  

class CEmployeeRs : public CADORecordBinding
{
BEGIN_ADO_BINDING(CEmployeeRs)

    //Column empid is the 1st field in the recordset   

    ADO_VARIABLE_LENGTH_ENTRY2(1, adVarChar, m_sz_empid, 
         sizeof(m_sz_empid), lemp_empidStatus, TRUE)

    ADO_VARIABLE_LENGTH_ENTRY2(2, adVarChar, m_sz_fname, 
         sizeof(m_sz_fname), lemp_fnameStatus, TRUE)

    ADO_VARIABLE_LENGTH_ENTRY2(4, adVarChar, m_sz_lname, 
         sizeof(m_sz_lname), lemp_lnameStatus, TRUE)
   
END_ADO_BINDING()

public:

   CHAR  m_sz_empid[10];
   ULONG lemp_empidStatus;
   CHAR   m_sz_fname[40];
   ULONG  lemp_fnameStatus;
   CHAR   m_sz_lname[41];
   ULONG  lemp_lnameStatus;
};