Ejemplo de las propiedades CursorType, LockType y EditMode (VC++)

Se aplica a: Access 2013, Office 2013

En este ejemplo se muestra cómo establecer el valor de las propiedades CursorType y LockType antes de que se abra un objeto Recordset. También se muestra el valor de la propiedad EditMode en diversas condiciones. Se requiere la función EditModeOutput para que pueda ejecutarse este procedimiento.

 
// BeginEditModeCpp 
#import "C:\Program Files\Common Files\System\ADO\msado15.dll" no_namespace rename("EOF", "EndOfFile") 
 
#include <ole2.h> 
#include <stdio.h> 
#include <conio.h> 
 
// Function declaration 
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);}; 
void EditModeX(void); 
void EditModeOutput(char *, int); 
void PrintProviderError(_ConnectionPtr pConnection); 
void PrintComError(_com_error &e); 
 
/////////////////////////////////////////////////////////// 
// // 
// Main Function // 
// // 
/////////////////////////////////////////////////////////// 
void main() 
{ 
 if(FAILED(::CoInitialize(NULL))) 
 return; 
 
 EditModeX(); 
 
 // Wait here for the user to see the output 
 printf("\n\nPress any key to continue..."); 
 getch(); 
 
 ::CoUninitialize(); 
} 
 
/////////////////////////////////////////////////////////// 
// // 
// EditModeX Function // 
// // 
/////////////////////////////////////////////////////////// 
void EditModeX(void) 
{ 
 // Define ADO object pointers. 
 // Initialize pointers on define. 
 // These are in the ADODB:: namespace. 
 _RecordsetPtr pRstEmployees = NULL; 
 _ConnectionPtr pConnection = NULL; 
 
 HRESULT hr = S_OK; 
 
 _bstr_t strCnn("Provider='sqloledb';Data Source='MySqlServer';" 
 "Initial Catalog='pubs';Integrated Security='SSPI';"); 
 
 try 
 { 
 // Open a connection 
 TESTHR(pConnection.CreateInstance(__uuidof(Connection))); 
 hr = pConnection->Open(strCnn,"","",adConnectUnspecified); 
 
 // Open recordset with data from employee table 
 TESTHR(pRstEmployees.CreateInstance(__uuidof(Recordset))); 
 
 pRstEmployees->CursorLocation = adUseClient; 
 pRstEmployees->CursorType = adOpenStatic; 
 pRstEmployees->LockType = adLockBatchOptimistic; 
 
 pRstEmployees->Open("employee", 
 _variant_t((IDispatch *) pConnection,true), 
 adOpenStatic,adLockBatchOptimistic,adCmdTable); 
 
 // Show the EditMode property under different editing states. 
 pRstEmployees->AddNew (); 
 pRstEmployees->Fields->Item["emp_id"]->Value = 
 (_bstr_t)("T-T55555M"); 
 pRstEmployees->Fields->Item["fname"]->Value = 
 (_bstr_t)("temp_fname"); 
 pRstEmployees->Fields->Item["lname"]->Value = 
 (_bstr_t)("temp_lname"); 
 EditModeOutput("After AddNew: ", pRstEmployees->EditMode); 
 
 pRstEmployees->UpdateBatch(adAffectCurrent); 
 EditModeOutput("After Update: ", pRstEmployees->EditMode); 
 
 pRstEmployees->Fields->Item["fname"]->Value = (_bstr_t)("test"); 
 EditModeOutput("After Edit: ", pRstEmployees->EditMode); 
 
 // Delete new record because this is a demonstration. 
 pConnection->Execute("DELETE FROM employee WHERE emp_id = " 
 "'T-T55555M'", NULL, adCmdText); 
 } 
 catch(_com_error &e) 
 { 
 // Notify the user of errors if any. 
 // Pass a connection pointer accessed from the Recordset. 
 PrintProviderError(pConnection); 
 PrintComError(e); 
 } 
 
 // Clean up objects before exit. 
 if (pRstEmployees) 
 if (pRstEmployees->State == adStateOpen) 
 pRstEmployees->Close(); 
 if (pConnection) 
 if (pConnection->State == adStateOpen) 
 pConnection->Close(); 
} 
 
/////////////////////////////////////////////////////////// 
// // 
// EditModeOutput() Function // 
// // 
/////////////////////////////////////////////////////////// 
void EditModeOutput(char *strTemp, int intEditMode) 
{ 
 // Print report based on the value of the EditMode property. 
 printf("\n%s", strTemp); 
 printf("\n EditMode = "); 
 
 switch (intEditMode) 
 { 
 case adEditNone : 
 printf("adEditNone"); 
 break; 
 case adEditInProgress : 
 printf("adEditInProgress"); 
 break; 
 case adEditAdd : 
 printf("adEditAdd"); 
 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; 
 
 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("\n\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); 
} 
 
// EndEditModeCpp