error: name followed by '::' must be a class or namespace name

I'm trying to build my first ATL DLL project, in which I'm using ADODB. The issue here is that I'm getting each ADODB class underlined

ADODB::_ConnectionPtr spADOConnection; 

when I pass the mouse over on ADODB::_ConnectionPtr I get name followed by '::' must be a class or namespace name spADOConnection I get expected a ';'. What's the mean of this, please? How do I to fix it please?

Thanks a lot!

1 Answer

The compiler is unable to locate the declaration of ADODB. Make sure you include the relevant header in the translation unit where the compiler complains.