error C2227: left of '->QueryInterface' must point to class/struct/union 是什么错误啊
d:\program files\microsoft visual studio\vc98\include\comip.h(690) : error C2227: left of '->QueryInterface' must point to class/struct/union
d:\program files\microsoft visual studio\vc98\include\comip.h(75) : see reference to function template instantiation 'long __thiscall _com_ptr_t<class _com_IIID<struct ADOCG::_Connection,&struct __s_GUID _GUID_00000550_0000_0010_8000_00aa006
d2ea4> >::_QueryInterface(const enum CRecordset::OpenType &)' being compiled
是什么错误啊?