Mining depends on a server side FLHook plugin. In most instances, SP will yield nothing. Singleplayer is meant to be nothing more than a open sandbox for testing.
Are you mining for fun or for money? I'm not sure if mining yields work in SP. As far as I'm aware, there is a "plugin" on the server that makes mining work the way it does.
If you need cash in SP, you can type "cash x" into the chat, where x is how much money you'd like (or just hold down the 9 key for max credits.
You can also teleport to any base of your choice in SP by typing "b Base Name" (Capitalization is important!).
I do know about the chat commands, but I was just trying to play the game without cheating in large amounts of credits. The jump command is pretty cool tho, and it will even jump to a waypoint. And being able to have more than one ship in sp is really awesome.
After shooting a large amount of debris, I figured mining depended on flhook running on the server, but I wanted to make sure. I'd love to come play on the server but I run Linux and I can't seem to get the servers to show up when trying to connect to multiplayer so until I figure out the problem I play single player. Well, even without mining, this is still one of the best mods and single player is still fun.