Erzhuo Wang's SQL code

You pretty clearly use Eclipse and presumably just pressed "add all files" or whatever in the Eclipse git plugin to create this review request, and as a result a bunch of auto-generated or otherwise irrelevant files made it in that shouldn't be here. I'll do my best to review what you have here, but its going to be difficult for me to make any progress on this.

And in the future, you might consider actually looking at the reviews that you create before submitting them, since it should be extremely obvious that I wouldn't want to merge in files like this.