All categories are gone! What happened? How do I fix it?

A client of mine uses ZenCart and he recently did something to erase all products and categories. I checked the system... they're not there! What did he do, and how do I fix it? He did it accidentally, so I'm sure it was a one-button thing.

Also, if there's a way to revert to a previous state, that should suffice. How would I do that?
Thanks.

You will need to restore from your most recent database backup.

Ok, great! How do I do that?

https://www.zen-cart.com/tutorials/index.php?article=103

The restore instruction is towards the bottom of that page.

Hmm... ok. But what if I did not make a backup? Does this system save itself every so often? I really need to restore my files.

There is no automatic backup that I know of. You could ask the hosting service.

I was going to ask you if you had a backup file in my previous message; but I kind of had the feeling you didn't.

Before you fully surrender the project to your client, always remember to provide them the backup files, so in case they screw up, you have them covered.

ALWAYS BACKUP

No pain, no gain. Amen. Though, as you mentioned, there might be an alternative solution since your customer only clicked on something to erase the categories.