Returns an interface pointer on the data source object that created the session.
HRESULT GetDataSource ( REFIID riid, IUnknown **ppDataSource);
[in] The IID of the interface on which to return a pointer.
[out] A pointer to memory in which to return the interface pointer. If IGetDataSource::GetDataSource fails, it must attempt to set *ppDataSource to a null pointer.
The method succeeded.
A provider-specific error occurred.
ppDataSource was a null pointer.
The object that created this session did not support the interface specified in riid.