Ejemplo del método NextRecordset (VC++)

Se aplica a: Access 2013, Office 2013

En este ejemplo se utiliza el método NextRecordset para ver los datos de un conjunto de registros que utiliza una instrucción compuesta formada por tres instrucciones SELECT.

 
// BeginNextRecordsetCpp 
#import "C:\Program Files\Common Files\System\ADO\msado15.dll" no_namespace rename("EOF", "EndOfFile") 
 
#include <stdio.h> 
#include <ole2.h> 
#include <conio.h> 
#include <stdlib.h> 
 
//Function Declaration. 
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);}; 
void NextRecordsetX(void); 
void PrintProviderError(_ConnectionPtr pConnection); 
void PrintComError(_com_error &e); 
 
/////////////////////////////////////////////////////////// 
// // 
// Main Function // 
// // 
/////////////////////////////////////////////////////////// 
void main() 
{ 
 if(FAILED(::CoInitialize(NULL))) 
 return; 
 
 NextRecordsetX(); 
 
 ::CoUninitialize(); 
} 
 
////////////////////////////////////////////////// 
// // 
// NextRecordsetX Function // 
// // 
////////////////////////////////////////////////// 
 
void NextRecordsetX(void) 
{ 
 // Define ADO object pointers. 
 // Initialize pointers on define. 
 // These are in the ADODB:: namespace. 
 _RecordsetPtr pRstCompound = NULL; 
 
 // Define Other Variables 
 HRESULT hr = S_OK; 
 _variant_t index; 
 index.vt = VT_I2; 
 
 // Assign connection string to a variable. 
 _bstr_t strCnn("Provider='sqloledb';Data Source='MySqlServer';" 
 "Initial Catalog='pubs';Integrated Security='SSPI';"); 
 
 try 
 { 
 // Open recordset from Authors table. 
 TESTHR(pRstCompound.CreateInstance(__uuidof(Recordset))); 
 
 // Pass the Cursor type and Lock type to the Recordset. 
 pRstCompound->Open("SELECT * FROM authors; SELECT * FROM stores;" 
 "SELECT * FROM jobs", strCnn, adOpenForwardOnly, 
 adLockReadOnly, adCmdText); 
 
 // Display results from each SELECT statement. 
 int intCount = 1; 
 while(!(pRstCompound==NULL)) 
 { 
 printf("\n\nContents of recordset #%d\n", intCount); 
 
 while(!pRstCompound->EndOfFile) 
 { 
 index.iVal = 0; 
 printf("%s\t", (LPCSTR)(_bstr_t)pRstCompound-> GetFields()->GetItem(& index)->Value); 
 index.iVal = 1; 
 printf("%s\n", (LPCSTR)(_bstr_t)pRstCompound-> Fields->GetItem(& index)->Value); 
 
 pRstCompound->MoveNext(); 
 
 int intLine = intLine + 1; 
 if (intLine % 22 == 0) 
 { 
 printf("\nPress any key to continue..."); 
 getch(); 
 
 //Clear the screen for the next display. 
 system("cls"); 
 } 
 } 
 long lngRec = 0; 
 pRstCompound = pRstCompound-> 
 NextRecordset((VARIANT *)lngRec); 
 
 printf("\nPress any key to continue..."); 
 getch(); 
 intCount = intCount + 1; 
 } 
 } 
 catch(_com_error &e) 
 { 
 // Notify the user of errors if any. 
 // Pass a connection pointer accessed from the Recordset. 
 _variant_t vtConnect = pRstCompound->GetActiveConnection(); 
 
 // GetActiveConnection returns connect string if connection 
 // is not open, else returns Connection object. 
 switch(vtConnect.vt) 
 { 
 case VT_BSTR: 
 PrintComError(e); 
 break; 
 case VT_DISPATCH: 
 PrintProviderError(vtConnect); 
 break; 
 default: 
 printf("Errors occured."); 
 break; 
 } 
 } 
 
 // Clean up objects before exit. 
 if (pRstCompound) 
 if (pRstCompound->State == adStateOpen) 
 pRstCompound->Close(); 
} 
 
/////////////////////////////////////////////////////////// 
// // 
// 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("\t Error number: %x\t%s", 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); 
} 
// EndNextRecordsetCpp