The thing about "expert systems" is that they're just glorified database query. (And yes, you can do also 'semantic' inference in a DB simply by adding some views. It's not generally done because it's quite computationally expensive even for very simple taxonomy structures, i.e. 'A implies B which implies C and foo is A, hence foo is C'.)
Database query is of course ubiquitous, but not generally thought of as 'AI'.