I have an entity of type A with a referenced member entity of type B. I want to insert a relationship between an instance of A to an existing instance of B without having to fetch B.
Is there a way to do it simply by ID? Something like:
B mockB = new B();
mockB.id = "id_persisted_b";
instanceA.setB(mockB);
Thanks.
If you are using JPA you can use EntityManager.getReference() to obatin a proxy of the object without fetching all the fields, e.g.:
B mockB = entityManager.getReference(B.class, "id_persisted_b");
instanceA.setB(mockB);
If you use Fetch type LAZY hibernate will not load the object, it will load only a reference to it when you need. Is like having just the PrimaryKey of the element. It does that automatically.
Lazy fetching decides whether to load child objects while loading the Parent Object. You need to do this setting respective hibernate mapping file of the parent class.
Lazy = true (means not to load child). By default the lazy loading of the child objects is true.
