I am using gcloud database, it is a mysql db, but to connect from outside i must use this connection string
and add some libs
can I connect from cuba to this database and how?
Now Studio supports only certain JDBC drivers with partially hardcoded URLs, so you cannot connect to a jdbc:google:mysql: server from Studio.
I would suggest using a local MySQL instance in development stage, and switch to cloud DB in production. If you use Tomcat in production, see this section for information on how to separate development and production settings of the database connection (see description of conf/Catalina/localhost folder). If you build WAR files, you can include a custom context.xml file in it - see Deployment settings in Studio.