Messed up site after running MySQL query?

While installing Multi-DB with the instructions provided, I entered this code: http://pastebin.com/s7yEUu9U

Now my entire site is messed up and cannot be accessed. Is there any way I could undo this? I don't have a backup, and WP's Auto-Repair isn't working. Also, what did I do wrong? I received a MySQL query error and then when I refreshed my site, it was no longer accessible.