在雙向OneToOne關係中刪除子實體

Question

我在一對一關係中有以下類。

DrivingLicense.java 
@Entity 
@Table(name = "DRIVING_LICENSE") 
public class DrivingLicense { 
    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO) 
    @Column(name = "LICENSE_NUMBER") 
    private int licenseNumber; 
    @Column(name = "DATE_OF_ISSUE") 
    private Date dateOfIssue; 

    @OneToOne 
    @JoinColumn(name = "PERSON_ID") 
    private Person person; 
} 

和

Person.java 
@Entity 
@Table(name = "PERSON") 
public class Person { 
    @Id 
    @GeneratedValue(strategy = GenerationType.AUTO) 
    @Column(name = "PERSON_ID") 
    private int personId; 
    @Column(name = "PERSON_NAME", nullable = false, length = 30) 
    private String personName; 

    @OneToOne(mappedBy = "person", cascade = CascadeType.ALL) 
    private DrivingLicense drivingLicense; 
} 

現在，當我嘗試刪除駕駛執照的實體，然後它不是刪除它，我很困惑，如何刪除單獨駕駛執照？

entityManager.getTransaction().begin(); 

    DrivingLicense drivingLicense = entityManager.find(DrivingLicense.class, 6); 
    entityManager.remove(drivingLicense); 
    entityManager.getTransaction().commit(); 

更新

，而不是刪除空兩個選擇

Hibernate: select drivinglic0_.LICENSE_NUMBER as LICENSE_NUMBER1_0_0_, drivinglic0_.DATE_OF_ISSUE as DATE_OF_ISSUE2_0_0_, drivinglic0_.PERSON_ID as PERSON_ID3_0_0_, person1_.PERSON_ID as PERSON_ID1_1_1_, person1_.PERSON_NAME as PERSON_NAME2_1_1_ from DRIVING_LICENSE drivinglic0_ left outer join PERSON person1_ on drivinglic0_.PERSON_ID=person1_.PERSON_ID where drivinglic0_.LICENSE_NUMBER=? 
Hibernate: select drivinglic0_.LICENSE_NUMBER as LICENSE_NUMBER1_0_1_, drivinglic0_.DATE_OF_ISSUE as DATE_OF_ISSUE2_0_1_, drivinglic0_.PERSON_ID as PERSON_ID3_0_1_, person1_.PERSON_ID as PERSON_ID1_1_0_, person1_.PERSON_NAME as PERSON_NAME2_1_0_ from DRIVING_LICENSE drivinglic0_ left outer join PERSON person1_ on drivinglic0_.PERSON_ID=person1_.PERSON_ID where drivinglic0_.PERSON_ID=? 

其燒成爲什麼這些2個選擇被解僱？

Answer 1

嘗試刪除drivingLicense從其各自Person第一：

entityManager.getTransaction().begin(); 

DrivingLicense drivingLicense = entityManager.find(DrivingLicense.class, 6); 

Person person = drivingLicense.getPerson(); 
person.setDrivingLicense(null); 
entityManager.merge(person); 

entityManager.remove(drivingLicense); 

entityManager.getTransaction().commit();