How Do I Reference a Property in My Provider?

Find the property group and property ID for the property you want. (See in the OLE DB Programmer's Reference.)

The following example assumes you are trying to get a property from the rowset. The code for using the session or command is similar, but uses a different interface.

Create a CDBPropset object using the property group as the parameter to the constructor. For example:

CDBPropSet propset(DBPROPSET_ROWSET);

Call AddProperty, passing it the Property ID and a value to be assigned to the property. The type of the value depends on the property you are using.

CDBPropSet propset(DBPROPSET_ROWSET);
propset.AddProperty(DBPROP_IRowsetChange, true);
propset.AddProperty(DBPROP_UPDATABILITY,
DBPROPVAL_UP_INSERT | DBPROPVAL_UP_CHANGE | DBPROPVAL_UP_DELETE);

Use the data member m_spUnkSite to get the pointer to the object that created your object.

CAgentRowset<CMyProviderCommand>* pRowset = (CAgentRowset<CMyProviderCommand>*) pThis;

CComQIPtr<IRowsetInfo, &IID_IRowsetInfo> spRowsetProps = pRowset;

Use the IRowset interface to call GetProperties. Pass the property set as a parameter. Here's the final code:

CAgentRowset<CMyProviderCommand>* pRowset = (CAgentRowset<CMyProviderCommand>*) pThis;

CComQIPtr<IRowsetInfo, &IID_IRowsetInfo> spRowsetProps = pRowset;

set.AddPropertyID(DBPROP_BOOKMARKS);
DBPROPSET* pPropSet = NULL;
ULONG ulPropSet = 0;
HRESULT hr;

if (spRowsetProps)
   hr = spRowsetProps->GetProperties(1, &set, &ulPropSet, &pPropSet);

if (pPropSet)
{
   CComVariant var = pPropSet->rgProperties[0].vValue;
   CoTaskMemFree(pPropSet->rgProperties);
   CoTaskMemFree(pPropSet);

   if (SUCCEEDED(hr) && (var.boolVal == VARIANT_TRUE))
   {
      …
   }
}