Multiple sites relying on one database is pretty simple.
For instance, I have this site: https://retailertoolkit.com/ which serves Real Estate websites with their Listings but also Hotel Reservation Bookings.
Couple things to consider, do you have "other people" that have access to Insert routines? If so, you may want to consider additional security like multiple access Connections. This allows you to shut down that connection if someones local computer gets compromised.
Additionally, use a History table in your DB that logs IP address and what account is being accessed... I don't know what you are doing other than multiple sites from one DB but IF other people will have access, take the time to create ways to track if someone gets compromised.