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

I also faced the same situation. By setting following annotation above the property made it solve the exception prompted.

The Exception I faced.

Exception in thread "main" java.lang.IllegalStateException: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.model.Car_OneToMany

To overcome, the annotation I used.

    @OneToMany(cascade = {CascadeType.ALL})
    @Column(name = "ListOfCarsDrivenByDriver")
    private List listOfCarsBeingDriven = new ArrayList();

What made Hibernate throw the exception:

This exception is thrown at your console because the child object I attach to the parent object is not present in the database at that moment.

By providing @OneToMany(cascade = {CascadeType.ALL}) , it tells Hibernate to save them to the database while saving the parent object.