My site is still dead tho, so I guess I didn’t expect it was a DB fault.
I assume you’ve fixed this as the post is quite old, but to anyone else that has killed their site, this might be useful:
Did you change the database prefix using the Better WP Security plugin after creating the backup you are restoring?
If so:
Open the file called ‘wp-config.php’ which is located in the site root, and look for the bit called ‘$table_prefix =’. You need to change the prefix here to match the one from the backup, more than likely it will need to be changed to ‘wp_’ (the standard install prefix) and re-uploaded to the site.
Otherwise, your site is trying to find a database that isn’t technically there anymore.
At the same time, delete the file in the root called .htaccess. This is an important file, you can get WordPress to restore it once your back in by going to Settings>Permalinks and hitting Save again.