codice:
// Open_Close_Methods.cpp
// compile with: /EHsc
#import "msado15.dll" no_namespace rename("EOF", "EndOfFile")
#include [list=1]
#include <stdio.h>
#include <conio.h>
#include "icrsint.h"
// class extracts only fname,lastname and hire_date from employee table
class CEmployeeRs : public CADORecordBinding {
BEGIN_ADO_BINDING(CEmployeeRs)
// Column fname is the 2nd field in the table
ADO_VARIABLE_LENGTH_ENTRY2(2, adVarChar, m_sze_fname,
sizeof(m_sze_fname), le_fnameStatus, FALSE)
// Column lname is the 4th field in the table.
ADO_VARIABLE_LENGTH_ENTRY2(4, adVarChar, m_sze_lname,
sizeof(m_sze_lname), le_lnameStatus, FALSE)
// Column hiredate is the 8th field in the table.
ADO_VARIABLE_LENGTH_ENTRY2(8, adDBDate,m_sze_hiredate,
sizeof(m_sze_hiredate), le_hiredateStatus, TRUE)
END_ADO_BINDING()
public:
CHAR m_sze_fname[21];
ULONG le_fnameStatus;
CHAR m_sze_lname[31];
ULONG le_lnameStatus;
DBDATE m_sze_hiredate;
ULONG le_hiredateStatus;
};
// Function declarations
inline void TESTHR(HRESULT x) { if FAILED(x) _com_issue_error(x); };
void OpenX();
void PrintProviderError(_ConnectionPtr pConnection);
void PrintComError(_com_error &e);
int main() {
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 pRstEmployee = NULL;
_ConnectionPtr pConnection = NULL;
// Define string variables.
_bstr_t strCnn("Provider='sqloledb'; Data Source='My_Data_Source'; Initial Catalog='pubs'; Integrated Security='SSPI';");
IADORecordBinding *picRs = NULL; // Interface Pointer declared.
CEmployeeRs emprs; // C++ Class object
DBDATE varDate;
try {
// open connection and record set
TESTHR(pConnection.CreateInstance(__uuidof(Connection)));
pConnection->Open(strCnn, "", "", adConnectUnspecified);
TESTHR(pRstEmployee.CreateInstance(__uuidof(Recordset)));
pRstEmployee->Open("Employee", _variant_t((IDispatch *)pConnection,true),
adOpenKeyset, adLockOptimistic, adCmdTable);
// Open an IADORecordBinding interface pointer for Binding Recordset to a class.
TESTHR(pRstEmployee->QueryInterface(__uuidof(IADORecordBinding),(LPVOID*)&picRs));
// Bind the Recordset to a C++ Class here.
TESTHR(picRs->BindToRecordset(&emprs));
// Assign first employee record's hire date to variable, then change hire date.
varDate = emprs.m_sze_hiredate;
printf("Original data\n");
printf("\tName - Hire Date\n");
printf(" %s %s - %d/%d/%d\n\n",
emprs.le_fnameStatus == adFldOK ?
emprs.m_sze_fname : "<NULL>",
emprs.le_lnameStatus == adFldOK ?
emprs.m_sze_lname : "<NULL>",
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.month : 0,
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.day : 0,
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.year : 0);
emprs.m_sze_hiredate.year = 1900;
emprs.m_sze_hiredate.month = 1;
emprs.m_sze_hiredate.day = 1;
picRs->Update(&emprs);
printf("\nChanged data\n");
printf("\tName - Hire Date\n");
printf(" %s %s - %d/%d/%d\n\n",
emprs.le_fnameStatus == adFldOK ?
emprs.m_sze_fname : "<NULL>",
emprs.le_lnameStatus == adFldOK ?
emprs.m_sze_lname : "<NULL>",
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.month : 0,
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.day : 0,
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.year : 0);
// Requery Recordset and reset the hire date.
pRstEmployee->Requery(adOptionUnspecified);
// Open IADORecordBinding interface pointer for Binding Recordset to a class.
TESTHR(pRstEmployee->QueryInterface(__uuidof(IADORecordBinding), (LPVOID*)&picRs));
// Rebind the Recordset to a C++ Class here.
TESTHR(picRs->BindToRecordset(&emprs));
emprs.m_sze_hiredate = varDate;
picRs->Update(&emprs);
printf("\nData after reset\n");
printf("\tName - Hire Date\n");
printf(" %s %s - %d/%d/%d", emprs.le_fnameStatus == adFldOK ?
emprs.m_sze_fname : "<NULL>",
emprs.le_lnameStatus == adFldOK ?
emprs.m_sze_lname : "<NULL>",
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.month : 0,
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.day : 0,
emprs.le_hiredateStatus == adFldOK ?
emprs.m_sze_hiredate.year : 0);
}
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 (pRstEmployee)
if (pRstEmployee->State == adStateOpen)
pRstEmployee->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;
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);
}
}
}
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);
}
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