Can JavaScript connect with MySQL? If so, how?
YES? Have a look a meteor. Links:
http://meteor.com/screencast and http://net.tutsplus.com/tutorials/javascript-ajax/whats-this-meteor-thing/
I don't understand how it is done. But Nettuts+ put this thing in the javascript-ajax section, maybe magic happens.
It also shows some way to connect and insert to MongoDB with JS, like this:
Products.insert({Name : "Hammer", Price : 4.50, InStock : true});
Products.insert({Name : "Wrench", Price : 2.70, InStock : true});
Products.insert({Name : "Screw Driver", Price : 3.00, InStock : false});
Products.insert({Name : "Drill", Price : 5.25, InStock : true});