This example uses the NextRecordset method to view the data in a recordset that uses a compound command statement made up of three separate SELECT statements.
#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=srv;"
"Initial Catalog=Pubs;User Id=sa;Password=;");
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;
}
}
}
///////////////////////////////////////////////////////////
// //
// 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,
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);
}