I'm not sure how to do it in a manner which would be considered effecient... but you can run multilayered queries (selects within selects) as well as conditional logic in your queries.

Just play...

I'm sorry but I don't think anyone can gather what you're trying to do...

Running your own MySQL server does not REQUIRE any form of encryption...

Try safe mode or root (depending on your platform)

You're close but consult the MySQL (I'm assuming that's your db) documentation for the correct timecode format. I think its YYYYMMDDHHMMSS (and you may insert 0s wherever you want.) so:
SELECT...