How to fix the Hibernate “object references an unsaved transient instance - save the transient instance before flushing” error

Question

I receive following error when I save the object using Hibernate

object references an unsaved transient instance - save the transient instance before flushi         


        

Answer 1

This occurred for me when persisting an entity in which the existing record in the database had a NULL value for the field annotated with @Version (for optimistic locking). Updating the NULL value to 0 in the database corrected this.