Hibernate saveOrUpdate fails when I execute it on an empty table

Question

I am trying to insert or update a db record with the following code:

Category category = new Category(); 
category.setName('catName');
category.setId(1L);
categoryDao.saveOrUpdate(category);

When there is a category with id = 1 in the database, everything works. But if there is no entry with id = 1, I got the following exception:

org.hibernate.StaleStateException:
Batch update returned unexpected row count from update [0]; actual row count: 0; 
expected: 1:

Here are my class settings, getters and class constructors that are clear:

@Entity
public class Category {    
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String name;

    @ManyToOne
    private Category parent;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "parent")
    private List<Category> categories = new ArrayList<Category>();
}

In the console, I see this request for sleep mode:

update
    Category
set
    name=?,
    parent_id=?
where
    id=?

So it looks like hibernates tryis is updating the record, not inserting a new one. What am I doing wrong here?

Answer 1

This is by design.

Hibernate , . , , , .

Hibernate, generator="assigned" ( , ). .

. , , . ( , ).

, generator="assigned" merge. , : , , , .

Answer 2

, rowcount 0 else saveorupdate.