Hibernate : add child to parent collection - mysql

Question

I'm using Hibernate on a web project, which a have two different classes (Node, Interface)
Node
#Entity
#Table(name="NODES")
public class Node {
//...
#OneToMany(mappedBy="node", cascade={CascadeType.ALL, CascadeType.MERGE, CascadeType.PERSIST}, orphanRemoval=true)
private Set<Interface> interfaces = new HashSet<>();
//...
}
Interface
#Entity
#Table(name="INTERFACES")
public class Interface {
//...
#ManyToOne(fetch=FetchType.LAZY)
#JoinColumn(name="REF_NODE")
private Node node;
//...
}
Everything is fine,
My question is how can I add an Interface(chlid) to a Node(Parent) that already persisted? means if i already has some Node in the database with 2 Interfaces for exemple and I want to add the third one, how i can do it?
My first quick solution is to use native sql in Hibernate, like this:
public void addInteface(Interface i, Long idNode) {
//OpenSession..
Session session = HibernateUtil.getSessionFactory().openSession();
Transaction tx = null;
try {
//Start transaction
tx = session.beginTransaction();
//Native SQL in Hibernate
SQLQuery query = session.createSQLQuery("INSERT INTO INTERFACES (ID_INTERFACE, ALIAS, ID_NODE) VALUES (NULL, :Alias, :idNode)");
query.setParameter("ifAlias", i.getAlias());
query.setParameter("refNode", idNode);
//Some other parameters...
//Execute and Commit
query.executeUpdate();
tx.commit();
} catch (Exception e) {
if (tx != null) tx.rollback();
throw e;
} finally {
session.close();
}
}
It works, but it's not the best solution i believe.
NB: I found some topics here in stackoverflow with the almost same title but didn't answer my question.

Answer 1

It can be done in 2 ways.
1st Option:
node.getInterfaces().add(new Interface(....)); // you have orphan removal to true, this will work
session.saveOrUpdate(node);
tx.commit();
session.close();
Or
2nd OPtion
newInterface.setNode(nodeObject);
session.saveOrUpdate(newInterface);
tx.commit();
session.close();
In the above 2 methods, 2nd option works great compared to the first one. 1st one will pull all the children when you call getInterfaces(), which does not perform better.

Answer 2

//Syntax may not be on point, also some psuedcode
Lets say you want to add an interface to Node with an id that is 1:
Query query = session.createQuery("Select n from Node n where n.id = '1'");//JPQL
Node n = query.getSingleResult();
Then you will make a new Interface
Interface i = new Interface();
Then set the variables to what you want but also set the node
i.setVariables(..);
i.setNode(n);
Then update
session.merge(i);
Now all this is assuming generator id is correct and such.