IS embadded database is HSQL databse, not MySQL database.
Use Visual Dialplan GUI to work with embadded database.
Simply open is-db-single-select.vdp or multiselect vdp sample and connection to embadded database will be established (because these samples use embadded database).
If you installed IS on another server change localhost with IP of the server and it will work.
In Visual Dialplan you can see all tables, fields, execute SQL queries etc.
That’s the GUI I use to manage database when working with Integration Server, no matter if I work with MS SQL, MySQL or integrated HSQL.