Extern keyword and unresolved external symbols

Question

I drew a little graph in paint that explains my problem:

But it doesn't seem to show up when I use the <img> tag after posting?

Graph:

Answer 1

You need to instantiate the database outside of main(), otherwise you will just declare a local variable shadowing the global one.

GameServer.cpp:

#include GameSocket.h
Database db(1, 2, 3);
int main() {
   //whatever
}