Earlier quoted context omitted.
Here we go with the amateur legal stuff, but until a more educated comment comes up, as far as I know, it is a question of the drivers being GPL, and coding up against the drivers crosses the threshold.
Not only that, but MySQL AB considered their network protocol to be GPL as well, and went after anyone who tried to make a clean-room implementation of it. I don't know whether SUN and Oracle still pursue that strategy. Otherwise you could indeed bundle MySQL with some clean-room libraries to talk to the server.
That doesn't sound legal. You're allowed to clean-room implement anything aren't you?