That highly depends on your database needs, but the de facto client side standard is sqlite3. Now, this might or might not fit your bill, so tell us a bit more about your data and what you want to do with is.

Flash... Well, some users here have done something like this, at least for UI. Look into the rally game thread in the projects forum. Not sure about the character though, that again depends on what you want to do. But maybe it's more efficient for you to just stick with flash instead ofw the pain of bridging it into gamestudio?