AddNew Method Example (VC++)
This example uses the AddNew method to create a new record with the specified name.
// BeginAddNewCpp.cpp
// compile with: /EHsc /c
#import "msado15.dll" no_namespace rename("EOF", "EndOfFile")
#include <ole2.h>
#include <stdio.h>
#include "conio.h"
#include "icrsint.h"
// 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;
};
// Function declaration
inline void TESTHR(HRESULT x) { if FAILED(x) _com_issue_error(x); };
void AddNewX();
void PrintProviderError(_ConnectionPtr pConnection);
inline int myscanf(char* strDest, int n) {
char strExBuff[10];
char* pstrRet = fgets(strDest, n, stdin);
if (pstrRet == NULL)
return 0;
if (!strrchr(strDest, '\n'))
// Exhaust the input buffer.
do {
fgets(strExBuff, sizeof(strExBuff), stdin);
} while (!strrchr(strExBuff, '\n'));
else
// Replace '\n' with '\0'
strDest[strrchr(strDest, '\n') - strDest] = '\0';
return strlen(strDest);
}
int main() {
HRESULT hr = S_OK;
if (FAILED(::CoInitialize(NULL)))
return -1;
if (SUCCEEDED(hr)) {
AddNewX();
::CoUninitialize();
}
}
void AddNewX() {
// Define ADO object pointers. Initialize pointers on define.
_RecordsetPtr pRstEmployees = NULL;
_ConnectionPtr pConnection = NULL;
// Define Other variables
IADORecordBinding *picRs = NULL; // Interface Pointer declared.(VC++ Extensions)
CEmployeeRs emprs; // C++ class object
HRESULT hr = S_OK;
// Replace Data Source value with your server name.
_bstr_t strCnn("Provider='sqloledb'; Data Source='My_Data_Source'; Initial Catalog='pubs'; Integrated Security='SSPI';");
_bstr_t strId;
_bstr_t strMessage;
try {
// Open a connection
TESTHR(pConnection.CreateInstance(__uuidof(Connection)));
pConnection->Open(strCnn, "", "", adConnectUnspecified);
// 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 IADORecordBinding interface pointer 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: ");
myscanf(emprs.m_sz_empid, sizeof(emprs.m_sz_empid));
strId = emprs.m_sz_empid;
printf("Enter First Name: ");
myscanf(emprs.m_sz_fname, sizeof(emprs.m_sz_fname));
printf("Enter Last Name:");
myscanf(emprs.m_sz_lname, sizeof(emprs.m_sz_lname));
// Proceed if user entered 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);
}
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 occurred.");
break;
}
}
// Clean up objects before exit. Release the IADORecordset Interface here
if (picRs)
picRs->Release();
if (pRstEmployees)
if (pRstEmployees->State == adStateOpen)
pRstEmployees->Close();
if (pConnection)
if (pConnection->State == adStateOpen)
pConnection->Close();
}
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);
}
}
}