Data suddenly gone

Hi,
I Have problem with my data. about few days ago the data is already entry by user and has been printed.
but today I try to find the data it's not exist. Does any one know how to prevent or how to track the problems?

thx

Someone else may have a better solution, but as far as I know the best solution is going to either stand up a new server and restore it from the latest production backup or refresh and existing dev environment from the backup...
Do an analysis to determine which rows are missing from from the production environment and manually copy them back into production.

As far as making sure it doesn't happen again... Start cutting permissions. The number of people who have rights to modify production data should be VERY limited, preferably, the DBA only and perhaps a qualified backup to handle emergencies when the DBA is unavailable.

ok thx a lot