Should have nothing to do with your database. But, of course, if your site has a problem, the first thing I'd be doing is a full database backup. And a PHP file backup. If you're going to go mucking around trying to fix something you don't know how to fix, you'd better start with setting a restore point of sorts by making yourself a complete reliable backup.
Session handling is a PHP issue. Sometimes session data is configured to be stored in the database, and sometimes stored on the filesystem.
The most common cause of session handling being broken is having the hosting company do server alterations affecting folder permissions or recompiling (and/or upgrading) PHP and changing the compile/config settings in the process. Or upgrading PHP to a version that handles sessions differently than the previous version did.
The FAQ articles and related threads will go into more detail, but the basics are:
- /cache/ folder ... must be writable by Apache/PHP
- Folder specified by DIR_FS_SQL_CACHE in your configure.php files must also be writable
- Admin setting for Session Directory must match the DIR_FS_SQL_CACHE folder setting. The fix_cache_key utility in the Troubleshooting Addons section can help with that when your admin login isn't working
- server's PHP settings must have session handling enabled and allow for Zen Cart to create its own sessions etc. One way to check is to run zc_install and let it get to the system inspection screen and see if it throws any warning flags related to your PHP configuration
And for goodness sake, Ask Your Hosting Company what's been going on with the server since your store last worked. If YOU didn't change anything and suddenly the site is broken ... well ... all fingers point to whoever can change how the server operates. THEY should be the first place you pester.
