When it is gone.
FIRST
Stop. Do not create a new database with the same name, which complicates recovery.
CHECK YOUR OWN BACKUPS
A dump you downloaded, a backup plugin's remote storage, a copy on your computer.
CHECK SERVER-SIDE RESTORE POINTS
Where your plan includes JetBackup, browse database backups by date and restore.
Otherwise open a ticket immediately with the database name and the date you need.
RETENTION IS FINITE
A request made today may be possible and the same request in three weeks may not.
Speed matters more than anything else here.
CHECK FOR A STAGING COPY
If you cloned the database for staging, that copy may still exist and be recent enough to be useful.
IF THERE IS GENUINELY NO COPY
Some content may be recoverable from an archive service, which caches public pages. That recovers text, not structure or user data.
For a shop, the payment gateway holds transaction records independently.
AFTERWARDS
Set up backups properly, stored off the server. This is the lesson people learn once.
