How to store in the database a nested list of objects that do not have an id field?

Question

PostgreSQL

Good afternoon, help with the solution of the problem, it is not possible to save a nested list of objects:

{
    "total": 1,
    "School": [
        {
            
            "id": "12",
            "nmb": "59",
            "name": "Имени Ивана Неизвестного"
            "Classes": [
                {
                    "name": "Математика",
                    "value": 12,
                },
                {
                    "name": "Физика",
                    "value": 21"
                },
                {
                   "name": "Химия",
                    "value": 22"
                }
}

Help how to make a more optimal solution where each class corresponded to the id of the school. Can this be done with Hibernate
Thanks in advance

Answer 1

Well... Looks like for classes the natural key would be (id, name).
Where id are strings in School.
name is the name field in Classes
:-)