Note: I don't want to put try-catch around EVERY method's
If you've got database connection code in a lot of methods, then
that's your problem, not the database being offline now and then
(though you should also get that fixed).
You should use
try..catch on an high level point in your
application anyway, or use the proper error handling of the web or
application framework you're using, so you can display a nice "Something
went wrong"-screen instead of dumping the exception to the end user.
You don't want to add a "database online"-check before executing a
query, because between those two calls the database can go offline, or you
can have invalid input which makes the query throw an exception anyway.