How does the JPA CascadeType.PERSIST work ?

Question

In my example, Employee has an OneToOne relationship to Department with CascadeType.PERSIST. When I persist multiple Em

Answer 1

JPA maintains object identity and will not persist an existing object.

Change you code to be correct,

for(int i=1; i <= 10; i++) {
    Department department = new Department("Test Department");
    Employee e = new Employee("EMP" + i, department);
    em.persist(e);
}