Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1

I had one PO for example Person and the key is Long id;

Then I mannully called person.setId(0);

I thought then if the id is 0, Hibernate will set the id;

Howevere, it didn't and the Exception happended.

Then I deleted the code to set id to 0 and it worked OK.