CODEWITHSUNDEEP
javahibernateorm
Dmytro
Dmytro

Reputation: 2009

Hibernate autoupdate in single transaction

I have two entities — Person and Address that have many-to-one relationship. So while trying to experiment with cascading and autoupdating i saw some interesting thing(for me):

    @Transactional
    public void run() {
        Address address = new Address("UK", "London", "221B Baker Street");
        Person person = new Person("Sherlock", "Homes", address);

        personRepository.save(person); //saves address also because of cascading

        address = addressRepository.findByCity("London");

        Set<Person> persons = address.getPersons();
        persons.add(new Person("John", "Watson", address)); //insert fires
        persons.add(new Person("Mary", "Morstan", address)); //nothing happens
    }

As you can see i get Address instance(previously saved) and add two new Person-s to it. What i expected is that Hibernate would update the address by inserting this Persons-s but it only updates the first one. Do anyone know what is going on here? Thanks in advance.

Upvotes: 0

Views: 66

Answers (1)

asm0dey
asm0dey

Reputation: 2931

EDIT: initial answer was incorrect, here is correct one:

After some discussion in comments we've found that author has overriden equals and hashCode in his objects. Here is article about this. Briefly: if we override we override equals and hashCode method based on id of entity — than when we add object to Set it has id of null, when we add second object - it has same id, so it's considered to be a duplicate and isn't being added to collection, and, consequently, isn't being persisted to DB.

Upvotes: 1

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