Doesn't your question also answer itself? You don't have a backup. How do you expect to recover a database that was deleted when you do not have a backup?
Maybe you can look into it to see what tables it contains and maybe find something useful in the tables that hint the purpose of your database named "sys"?
Maybe you can look into it to see what tables it contains and maybe find something useful in the tables that hint the purpose of your database named "sys"?
There is no real way to recover it if you have absolutely no backups. Maybe check with your service provider to see if they keep backups. If it was extremely important data, you may be able to ship it to a forensics lab and see what they can scrape off. Otherwise, you're likely out of luck.
You neither share which operating system, which database server, whether you are using a root server or a cloud server. So you can hardly be helped.
A very small possibility to help you would be this command for the SSH console ...
Use at your own risk