OLE DB Open Database

Hi.
I Have some problem then i Use SQL Server Compact 3.5. So i can't open database.






Code Snippet

HRESULT hr;
IDBInitialize * pIDBInitialize = NULL;
IDBProperties * pIDBProperties = NULL;
IDBCreateSession * pIDBCrtSession = NULL;
DBPROPSET rgPropSets[1];
DBPROP rgProps[1];
ULONG iPropSet = 0;
ULONG iProp = 0;
ICommandText * pICmdText = NULL;
IDBCreateCommand * pIDBCrtCmd = NULL;
ICommandPrepare * pICmdPrepare = NULL;
ICommandWithParameters * pICmdWParams = NULL;
IAccessor * pIAcc = NULL;
ULONG cParams;
DBPARAMINFO * rgParamInfo = NULL;
OLECHAR * pNamesBuffer = NULL;
ULONG cBindings;
DBBINDING rgBindings[3];
ULONG cbRowSize;
HACCESSOR hAcc;
BYTE * pData = NULL;
DBPARAMS params;
LONG cRowsAffected;
CoInitialize(NULL);
// Specify the MyDB database as wzDbName.
WCHAR wzDbName[] = L"C:\Northwind.sdf";

// Initialize the property set values.and create the data source object.
for (ULONG i = 0; i < sizeof(rgProps)/sizeof(rgProps[0]); i++)
{
VariantInit(&rgProps[i].vValue);
}

hr = CoCreateInstance(CLSID_SQLSERVERCE_3_5, NULL, CLSCTX_INPROC_SERVER,
IID_IDBInitialize, (LPVOID *) &pIDBInitialize);
if (FAILED(hr))
{
//Send an error-specific message and do error handling.
goto Exit;
}

iProp = 0;
rgProps[iProp].dwPropertyID = DBPROP_INIT_DATASOURCE;
rgProps[iProp].dwOptions = DBPROPOPTIONS_REQUIRED;
rgProps[iProp].vValue.vt = VT_BSTR;
rgProps[iProp].vValue.bstrVal = SysAllocString(wzDbName);
if(!(rgProps[iProp].vValue.bstrVal))
{
hr = E_OUTOFMEMORY;
goto Exit;
}
iProp++;

iPropSet = 0;
rgPropSets[iPropSet].rgProperties = rgProps;
rgPropSets[iPropSet].cProperties = iProp;
rgPropSets[iPropSet].guidPropertySet = DBPROPSET_DBINIT;
iPropSet++;

// Set the properties into the provider's data source object.
pIDBInitialize->QueryInterface(IID_IDBProperties,(void**)&pIDBProperties);

hr = pIDBProperties->SetProperties(sizeof(rgPropSets)/sizeof(rgPropSets[iPropSet]),
rgPropSets);
if(FAILED(hr))
{
goto Exit;
}

// Create a session that supports commands.
hr = pIDBProperties->QueryInterface(IID_IDBCreateSession, (void **)
&pIDBCrtSession);

...........
Example from MSDN. .
So after pIDBProperties->QueryInterface hr become E_NOINTERFACE . And i dont know why it happens. database - is a sample database which tou can find in Microsoft SQL Server Compact Editionv3.5Samples.
Please help !