Organizing your app infrastructure with separation of concerns is always a good thing and the power of Docker to make this easy for you.
However if your database is your most central key element, you might want to consider using a managed database service for your database alone. So it is all well managed, software kept up to date and backup-ed. Hosting providers as Digital Ocean and AWS already provide Managed Database solutions out of the box.
The advantage of having your database separate is that then you can have multiple sites/apps - that can even span multiple servers, or working in a clusters of servers - all using the same database.
And you don't have to make separate projects for this in Wappler - the Database Manager can connect your straight to your Managed Database and you don't have to use databases with docker.
See: