You can't do it like that. switch makes decisions based on the value of a variable, but the only values that you can find in the array returned by that function are 0 and 1.
A keycode is different from a scancode. A keycode corresponds to your locale where as your scancode corresponds to your hardware. SDL has fantastic documentation on it.
http://wiki.libsdl.org/MigrationGuide#Input
The only thing that's wrong with the migration guide is that it actually somewhat lies about how to grab input. It says you only need to call SDL_SetRelativeMouseMode(SDL_TRUE); which you do need to call but there's one other. That would be SDL_SetWindowGrab(pWindow, SDL_TRUE);.