I created a project in JAVA spring boot. In this image I created two tables called Event and Seating, they have a relationship between them as one to many.

I also created a table called Layout and another table called Table. They have also a relationship between them as one to many, so one layout can have multiple tables.

That´s the controller that controls the front-end and back-end. So once I request come from or to the controller is using the @GetMapping and @PostMappint annotation.