Error Object Example

OLE DB Programmer's Reference

The code in this example illustrates the use of error objects in OLE DB error handling.

//////////////////////////////////////////////////////////////////////// // myHandleResult // // This function is called as part of the XCHECK_HR macro; it takes an // HRESULT, which is returned by the method called in the XCHECK_HR // macro, and the file and line number where the method call was made. // If the method call failed, this function attempts to get and display // the extended error information for the call from the IErrorInfo, // IErrorRecords, and ISQLErrorInfo interfaces. // //////////////////////////////////////////////////////////////////////// HRESULT myHandleResult    (    HRESULT              hrReturned,    LPCWSTR              pwszFile,    ULONG                ulLine) {    HRESULT              hr;    IErrorInfo *         pIErrorInfo               = NULL;    IErrorRecords *      pIErrorRecords            = NULL;    ULONG                cRecords;    ULONG                iErr;    // If the method called as part of the XCHECK_HR macro failed,    // we will attempt to get extended error information for the call.    if( FAILED(hrReturned) )    {       // Obtain the current error object, if any, by using the       // Automation GetErrorInfo function, which will give       // us back an IErrorInfo interface pointer if successful.       hr = GetErrorInfo(0, &pIErrorInfo);       // We've got the IErrorInfo interface pointer on the error object.       if( SUCCEEDED(hr) && pIErrorInfo )       {          // OLE DB extends the Automation error model by allowing          // error objects to support the IErrorRecords interface. This          // interface can expose information on multiple errors.          hr = pIErrorInfo->QueryInterface(IID_IErrorRecords,                                           (void**)&pIErrorRecords);          if( SUCCEEDED(hr) )          {             // Get the count of error records from the object.             CHECK_HR(hr = pIErrorRecords->GetRecordCount(&cRecords));                          // Loop through the set of error records, and             // display the error information for each one.             for( iErr = 0; iErr < cRecords; iErr++ )             {                myDisplayErrorRecord(hrReturned, iErr, pIErrorRecords,                                     pwszFile, ulLine);             }          }          // The object didn't support IErrorRecords. Display          // the error information for this single error.          else          {             myDisplayErrorInfo(hrReturned, pIErrorInfo, pwszFile,                                ulLine);          }       }       // There was no error object, so just display the HRESULT to the       // user.       else       {          wprintf(L"\nNo Error Info posted; HResult: 0x%08x\n"             L"File: %s, Line: %d\n", hrReturned, pwszFile, ulLine);       }    } CLEANUP:    if( pIErrorInfo )       pIErrorInfo->Release();    if( pIErrorRecords )       pIErrorRecords->Release();    return hrReturned; }

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