I really like this webserver+CGI/PHP frontend approach, even for just on your own little PC. So, use a minimal webserver and one of the web frontends. For Mysql, phpMyAdmin is well received among users, and there is the (now probably abandoned &mdash unfortunately) Perl frontend mysqltool. I've used both, and they do the job well.

For PostGres I have been playing with phpPgAdmin. It seems fine.

And I'm sure there are more alternatives, for both.