Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect)

Question

I have a java project that runs on a webserver. I always hit this exception.

I read some documentation, and found that pessimistic locking (or optimistic, but I read

Answer 1

First check your imports, when you use session, transaction it should be org.hibernate and remove @Transactinal annotation. and most important in Entity class if you have used @GeneratedValue(strategy=GenerationType.AUTO) or any other then at the time of model object creation/entity object creation should not create id. final conclusion is if you want pass id filed i.e PK then remove @GeneratedValue from entity class.