Exam 1z0-898 topic 1 question 17 discussion

Actual exam question from Oracle's 1z0-898

Question #: 17
Topic #: 1

Given two entities with one to-one association:
@Entity public class Person {
@Id Integer id;

}
@Entity public class PersonDetail {
@Id Integer id;

}
Which code fragment correctly defines the detail field that PersonDetail instance in removed if the person instance that references it is removed?

A. @OneToOne (optional = false) personDetail detail;
B. @OneToOne (optional = false) @mapsId PersonDetail Detail;
C. @ OneToOne (orphanremoval = true) PersonDetail Detail;
D. @ OneToOne (cascade = ORPHAN _ DELETE) @mapsId

Show Suggested Answer

Suggested Answer: C 🗳️
Orphan Removal in Relationships -
When a target entity in one-to-one or one-to-many relationship is removed from the relationship, it is often desirable to cascade the remove operation to the target entity. Such target entities are considered "orphans," and the orphanRemoval attribute can be used to specify that orphaned entities should be removed. For example, if an order has many line items and one of them is removed from the order, the removed line item is considered an orphan. If orphanRemoval is set to true, the line item entity will be deleted when the line item is removed from the order.
The orphanRemoval attribute in @OneToMany and @oneToOne takes a Boolean value and is by default false.
The following example will cascade the remove operation to the orphaned customer entity when it is removed from the relationship:
@OneToMany(mappedBy="customer", orphanRemoval="true")
public List<Order> getOrders() { ... }
Reference: Orphan Removal in Relationships

by xylofivo at April 4, 2025, 2:47 p.m.

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