text browser game

I'm pretty noobish at web coding / webdev.  I'm trying to figure out how I could write a browser game using only JavaScript on the client-side (ie. no browser plug-ins).  But I'm stuck on figuring out how to handle everything server-side.

The only thing I've thought of is to store everything in a SQL database, and just have the AJAX post some information to a PHP file that will take care of everything.  However, I'm wondering if there are other, better ways of doing this that I can't think of.  I'm also not sure about handling concurrent players because I haven't done very much with databases before, so I'm not sure whether I'll have to worry about race conditions or something.

Any ideas or advice would be appreciated.

>>14
AJAX still won't do that (you will have to poll at intervals)
Yes it will, and no you won't. This is the second time this week I see this fucking stupid misconception thrown around in /prog/.