Currently I have a monolithic application with some modules like financial and accounting. This application uses a single database and the modules are divided into schemas, so when I need to display the data on user interface or in a report I just need to do a simple query with a couple joins.
My question is, in a microservices structure where each module has his own database, how do I retrieve this data getting the same result as if I were in a single database?
When talking about splitting the database in the process of migrating a monolith to Microservices, there are some known patterns like:
Seems the database view or the database as a service could be a candidate in this case, but of course no one better than you can decide which one is viable in your project.
I highly recommend you to have a look at chapter 4 of "Monolith to Microservices" by Sam Newman.