johnsca
commented
8 years ago I'm fairly certain you actually have to use a different interface (mysql-shared) to do that with MySQL.
In contrast, the Postrgres charm does support changing the database name on the same relation, see interface:pgsql requires.py#L47
Pre-layers, we could use relation_set in the db-relation-joined script to tell mysql the name of the database we'd like to use. This is particularly handy when installing software that's expecting a specific database name and changing that behavior is cumbersome.
It'd be good to have a way to communicate this in the db.joined state, to override the default of setting the database name equal to the service name.