what is @JoinColumn and how it is used in Hibernate

Question

I have been reading a lot about @JoinColumn but I still don\'t get the idea behind it.

Patient Table

CREATE TABLE patient (
patient_id BIGINT NOT NUL         


        

Answer 1

Why is that the patient_id (generated column which is a FK) in the Vehicle Table doesn't have any value when I run my code?

All @JoinColumn does is to specify a column for joining an entity association or element collection. Since you have made @JoinColumn associated with Patient class object, that's why foreign key is created on Patient table.

For more please refer https://docs.jboss.org/hibernate/jpa/2.1/api/javax/persistence/JoinColumn.html