Path to becoming a back end Java Engineer

Yes, very much “Learn a database”. That means “Learn JDBC” (https://docs.oracle.com/javase/tutorial/jdbc/basics/index.ht...)

In fact, I’d suggest installing at least _two_ different dbs on your dev box, for example Postgres and MySQL. (Or, if you’re legacy-enterprise oriented, Oracle XE and MS SQL Server developer).

Then, select data from one, and insert into the other.

Bonus points if you avoid passwords in your checked-in code :-)