Delete - Worked Example

key : purple - original code / blue - new code

Step 1 :

Link the Delete menu item to an OnDelete() function within the View. Add the following code. The name Mr William Wordworth will be deleted from the database.

void CInterView::OnDelete()
{

_RecordsetPtr pRecordSet;
CInterDoc * pDoc;
pDoc = GetDocument();

HRESULT hr;
_bstr_t bstrQuery(
"SELECT * FROM Names WHERE ID = 76");
_variant_t vNull;
vNull.vt = VT_ERROR;
vNull.scode = DISP_E_PARAMNOTFOUND;

try
{

hr = pRecordSet.CreateInstance(_uuidof(Recordset));
if (SUCCEEDED(hr))
{

pRecordSet->PutRefActiveConnection(pDoc->m_pConnection);
hr = pRecordSet->Open(_variant_t(bstrQuery), vNull,
adOpenForwardOnly, adLockOptimistic, adCmdText);
if (!pRecordSet->GetadoEOF())
{

pRecordSet->Delete(adAffectCurrent);
pRecordSet->Close();

}

}

}
catch( _com_error &e )
{

TRACE( "Error:%08lx.\n", e.Error());
TRACE( "ErrorMessage:%s.\n", e.ErrorMessage());
TRACE( "Source:%s.\n", (LPCTSTR) _bstr_t(e.Source()));
TRACE( "Description:%s.\n", (LPCTSTR) _bstr_t(e.Description()));

}
catch(...)
{

TRACE( "\n*** Unhandled Exception ***\n" );

}

}

Click here for the basic exercise

Click here for the source code

Click here to return to menu