如何使用 Hibernate 仅更新数据库的一个属性...因为它由于 getter 和 setter 分配了 NULL 值？

Question

I am trying to update a row by using its primary key, the issue is that Hibernate updates entire row and since I have not passed values for any other attributes (For Ex: Attributes are empid, name salary and address. I will pass empid=1 and name to be updated. But it will set NULL to other 2 values ie address and salary) it assigns NULL to them. I want to Update only selective attributes;

I tried using saveOrUpdate but that too is either entering new or updating same row with NULL values. Is there any other solutions???

Answer 1

I figured the following works. The code below is the update method in my execution file which is called.

public void update(int empid,String name) {
    Session session = sc.openSession();
    Transaction t = session.beginTransaction();
    Query q = session.createQuery("from employee");
    List<?> l = q.getResultList();
    Iterator<?> it = l.iterator();
    employee e1 = (employee) it.next();
    String Address;
    int Salary;
    Salary=e1.getSalary();
    Address=e1.getAddress().toString();
    session.evict(e1);
    employee e2=new employee();
    e2.setEmpid(empid);
    e2.setName(name);
    e2.setAddress(Address);
    e2.setSalary(Salary);;
    session.saveOrUpdate(e2);
    t.commit();
    
}

Answer 2

If you can use hibernate, why don't you can use JPA?

var entity = repo.getById( id );
entity.setValue( value );
repo.save(); // or repo.saveAndFlush();

Answer 3

Try use the native sql to update

    Session session = sessionFactory.openSession();
    Transaction t = session.beginTransaction();
    Query query = session.createQuery("update employee e set e.name = 'newvalue' where e = 1");
    query.executeUpdate();
    t.commit();

I agree with Jan Tibar said that Jpa is more convenient than hibernate