how to update an entity with spring data jpa

Question

I have an entity and a Junit, I want to test that update method is working fine, but when I invoke save method from CrudRepository I get a new entry in my table instead of the u

Answer 1

One doesn't have to do any complex operations for this. In your service class you can do something like this.

 @Service
public class PersonServiceImpl implements PersonService {

    @Autowired
    private PersonRepository personRepository;

    @Override
    public Person updatePerson(Person oldPerson) throws Exception { 

      oldPerson.setId(oldPerson.getId()) ; // pass the associated id for which you want to update and set that id to the same person [ basically setting the same id to the oldPerson ] this way it will not create new entry because here we are not making new ID ] 

 //oldPerson.set others [ what is to be updated ]  


        return personRepository.save(oldPerson); // now save [old person with updated content but same id as it was before ]
    }
}

This solves the problem of creating new entry to the database and updates the same content with Id associate with that person.