Remarks
Contains a pointer to the OLE interface for the underlying DAO querydef object. This pointer is provided for completeness and consistency with the other classes. However, because MFC rather fully encapsulates DAO querydefs, you are unlikely to need it. If you do use it, do so cautiously — in particular, do not change the value of the pointer unless you know what you are doing.
For information about querydefs, see the article DAO Querydef in Visual C++ Programmer's Guide.