Recupero delle informazioni sugli errori
Si applica a: 
SQL Server Database SQL di Azure Istanza gestita di SQL di Azure Azure Synapse Analytics Piattaforma di strumenti analitici (PDW)
In questo esempio si ottengono informazioni dalle varie interfacce di errore esposte dal driver OLE DB per SQL Server.
// DumpErrorInfo queries MSOLEDBSQL error interfaces, retrieving available
// status or error information.
void DumpErrorInfo
(
IUnknown* pObjectWithError,
REFIID IID_InterfaceWithError
)
{
// Interfaces used in the example.
IErrorInfo* pIErrorInfoAll = NULL;
IErrorInfo* pIErrorInfoRecord = NULL;
IErrorRecords* pIErrorRecords = NULL;
ISupportErrorInfo* pISupportErrorInfo = NULL;
ISQLErrorInfo* pISQLErrorInfo = NULL;
ISQLServerErrorInfo* pISQLServerErrorInfo = NULL;
// Number of error records.
ULONG nRecs;
ULONG nRec;
// Basic error information from GetBasicErrorInfo.
ERRORINFO errorinfo;
// IErrorInfo values.
BSTR bstrDescription;
BSTR bstrSource;
// ISQLErrorInfo parameters.
BSTR bstrSQLSTATE;
LONG lNativeError;
// ISQLServerErrorInfo parameter pointers.
SSERRORINFO* pSSErrorInfo = NULL;
OLECHAR* pSSErrorStrings = NULL;
// Hard-code an English (United States) locale for the example.
DWORD MYLOCALEID = 0x0409;
// Only ask for error information if the interface supports
// it.
if (FAILED(pObjectWithError->QueryInterface(IID_ISupportErrorInfo,
(void**) &pISupportErrorInfo)))
{
wprintf_s(L"SupportErrorErrorInfo interface not supported");
return;
}
if (FAILED(pISupportErrorInfo->
InterfaceSupportsErrorInfo(IID_InterfaceWithError)))
{
wprintf_s(L"InterfaceWithError interface not supported");
return;
}
// Do not test the return of GetErrorInfo. It can succeed and return
// a NULL pointer in pIErrorInfoAll. Simply test the pointer.
GetErrorInfo(0, &pIErrorInfoAll);
if (pIErrorInfoAll != NULL)
{
// Test to see if it's a valid OLE DB IErrorInfo interface
// exposing a list of records.
if (SUCCEEDED(pIErrorInfoAll->QueryInterface(IID_IErrorRecords,
(void**) &pIErrorRecords)))
{
pIErrorRecords->GetRecordCount(&nRecs);
// Within each record, retrieve information from each
// of the defined interfaces.
for (nRec = 0; nRec < nRecs; nRec++)
{
// From IErrorRecords, get the HRESULT and a reference
// to the ISQLErrorInfo interface.
pIErrorRecords->GetBasicErrorInfo(nRec, &errorinfo);
pIErrorRecords->GetCustomErrorObject(nRec,
IID_ISQLErrorInfo, (IUnknown**) &pISQLErrorInfo);
// Display the HRESULT, then use the ISQLErrorInfo.
wprintf_s(L"HRESULT:\t%#X\n", errorinfo.hrError);
if (pISQLErrorInfo != NULL)
{
pISQLErrorInfo->GetSQLInfo(&bstrSQLSTATE,
&lNativeError);
// Display the SQLSTATE and native error values.
wprintf_s(L"SQLSTATE:\t%s\nNative Error:\t%ld\n",
bstrSQLSTATE, lNativeError);
// SysFree BSTR references.
SysFreeString(bstrSQLSTATE);
// Get the ISQLServerErrorInfo interface from
// ISQLErrorInfo before releasing the reference.
pISQLErrorInfo->QueryInterface(
IID_ISQLServerErrorInfo,
(void**) &pISQLServerErrorInfo);
pISQLErrorInfo->Release();
}
// Test to ensure the reference is valid, then
// get error information from ISQLServerErrorInfo.
if (pISQLServerErrorInfo != NULL)
{
pISQLServerErrorInfo->GetErrorInfo(&pSSErrorInfo,
&pSSErrorStrings);
// ISQLServerErrorInfo::GetErrorInfo succeeds
// even when it has nothing to return. Test the
// pointers before using.
if (pSSErrorInfo)
{
// Display the state and severity from the
// returned information. The error message comes
// from IErrorInfo::GetDescription.
wprintf_s(L"Error state:\t%d\nSeverity:\t%d\n",
pSSErrorInfo->bState,
pSSErrorInfo->bClass);
// IMalloc::Free needed to release references
// on returned values. For the example, assume
// the g_pIMalloc pointer is valid.
g_pIMalloc->Free(pSSErrorStrings);
g_pIMalloc->Free(pSSErrorInfo);
}
pISQLServerErrorInfo->Release();
}
if (SUCCEEDED(pIErrorRecords->GetErrorInfo(nRec,
MYLOCALEID, &pIErrorInfoRecord)))
{
// Get the source and description (error message)
// from the record's IErrorInfo.
pIErrorInfoRecord->GetSource(&bstrSource);
pIErrorInfoRecord->GetDescription(&bstrDescription);
if (bstrSource != NULL)
{
wprintf_s(L"Source:\t\t%s\n", bstrSource);
SysFreeString(bstrSource);
}
if (bstrDescription != NULL)
{
wprintf_s(L"Error message:\t%s\n",
bstrDescription);
SysFreeString(bstrDescription);
}
pIErrorInfoRecord->Release();
}
}
pIErrorRecords->Release();
}
else
{
// IErrorInfo is valid; get the source and
// description to see what it is.
pIErrorInfoAll->GetSource(&bstrSource);
pIErrorInfoAll->GetDescription(&bstrDescription);
if (bstrSource != NULL)
{
wprintf_s(L"Source:\t\t%s\n", bstrSource);
SysFreeString(bstrSource);
}
if (bstrDescription != NULL)
{
wprintf_s(L"Error message:\t%s\n", bstrDescription);
SysFreeString(bstrDescription);
}
}
pIErrorInfoAll->Release();
}
else
{
wprintf_s(L"GetErrorInfo failed.");
}
pISupportErrorInfo->Release();
return;
}