CODEWITHSUNDEEP
javahibernatesql-updatedatabase-relations
sergionni
sergionni

Reputation: 13510

Update table with FK column values from related table

Hibernate entities used. There are Address and Room entities and apropriate tables in DB.
Address can have multiple Rooms.

Both tables have address_Id and customerEmailAddress
These columns are FK in Room table,that references to Address table.

There is already Address record in DB.
It's needed to add several Rooms to this Address.

How to organize Hibernate relation with annotations between Address and Room, so Room table to be updated with appropriate attributes from Address:
address_Id and customerEmailAddress

Java part looks like:

    Room room = new Room();
    Address addr  = someService.getAddressFromSession();
    room.add(addr);
    entityManager.persist(room);
    Room room2 = new Room();
    room2.add(addr);
    entityManager.persist(room2);

DB outcome (Room table) should be following:
id||addressId|| customerEmailAddress
1 || 3               || [email protected]
2 || 3               || [email protected]

Upvotes: 0

Views: 108

Answers (1)

Yogendra Singh
Yogendra Singh

Reputation: 34367

You haven't mentioned about primary keys of both the tables. Assuming both the tables have their own primary keys, I think you can have standard mapping done between Address and Room objects using component model as below:

  1. Map address_id and customerEmailAddress as a component. Refer the documentation for component mapping here-- Hibernate Component Mapping.

  2. Add rooms in Address and One-To-Many relationship using component defined above and set cascade to All.

  3. Add address in Room as Many-To-One using component defined above.

  4. Define one addRoom method in Address as below(conceptually):

      public void addRoom(Room room){
       if(this.rooms == null){
           this.rooms = new ArrayList<Room>();
       }
       room.setAddress(this);
       this.rooms.add(room);
  }

  5. Now you can simply work at Address level. To save the room, add the room to address and save the address.

Hope this helps!

Upvotes: 1

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