CODEWITHSUNDEEP
jpaspring-dataspring-data-jpa
robert trudel
robert trudel

Reputation: 5749

Many to many relation no saved

I try without success to save a many to many relation.

In my lodger class

@ManyToMany(cascade = {CascadeType.PERSIST, CascadeType.MERGE}, mappedBy = "lodger")
private List<Contact> contactList;

In my contact class

@ManyToMany
@JoinTable(name = "lodger_contact", joinColumns = @JoinColumn(name = "contact_id"), inverseJoinColumns = @JoinColumn(name = "lodger_id"))
private List<Lodger> lodger;

How i save the relation

public void associateDissociateLodgerAndContact(Long lodgerId, List<Long> contactIdToDissociates, List<Long> contactIdToAssociates) {
    Lodger lodger = lodgerRepository.findOne(lodgerId);

    List<Contact> contactList;

    if (lodger.getContactList() == null) {
        lodger.setContactList(new ArrayList<>());
        contactList = lodger.getContactList();
    } else {
        contactList = lodger.getContactList();
    }

    if (contactIdToDissociates != null) {

        for (Iterator<Contact> iterator = contactList.iterator(); iterator.hasNext();) {
            Contact contact = iterator.next();

            for (Long contactId : contactIdToDissociates) {
                if (contact.getContactId().longValue() == contactId.longValue()) {
                    iterator.remove();
                    break;
                }
            }

        }
    }

    List<Contact> contactToAssign = contactRepository.findAll(contactIdToAssociates);

    lodger.getContactList().addAll(contactToAssign);
    lodgerRepository.save(lodger);
}

Before I do the save, I try to add 2 contact to lodger and remove one. Just before the save, i see there are 2 element in getContactList.

When I do the save, no query is done.

Upvotes: 0

Views: 46

Answers (1)

Ish
Ish

Reputation: 4154

Since this is bi-directional relationship, you should link/unlink both sides of the relationship. You are only updating the relationship from one side - from the Lodger side.

Upvotes: 1

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