Usually mySQL servers are closed to access from external IPs. Instead mySQL users are used to connect to remote host using SSH tunnel and then connect to mySQL server like from localhost.
We have add into Valentina Studio support of SSH connects to remote hosts. It is clear that it can be used for any remote DB server: Valentina Server, mySQL or PostgreSQL.
Also we have to push SSH parameters into the connection string of Valentina Reports, so now reports can connect to e.g. remote mySQL server by SSH tunnel also. Read in WIKI.