我一直在搞砸这个并在谷歌上搜索了大约 4 天，我对 Hibernate 注释如何与 JPA 注释一起工作感到疯狂。我有两个非常简单的实体：
学生
package com.vaannila.student;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.OneToMany;
import org.hibernate.annotations.Cascade;
import org.hibernate.annotations.CascadeType;
@Entity
public class Student {
@Id
@GeneratedValue
private long studentId;
private String studentName;
@OneToMany(orphanRemoval = true)
@Cascade(CascadeType.ALL)
@JoinTable(name = "STUDENT_PHONE", joinColumns = { @JoinColumn(name = "STUDENT_ID") }, inverseJoinColumns = { @JoinColumn(name = "PHONE_ID") })
private Set<Phone> studentPhoneNumbers = new HashSet<Phone>(0);
public Student() {
}
public Student(String studentName, Set<Phone> studentPhoneNumbers) {
this.studentName = studentName;
this.studentPhoneNumbers = studentPhoneNumbers;
}
public long getStudentId() {
return this.studentId;
}
public void setStudentId(long studentId) {
this.studentId = studentId;
}
public String getStudentName() {
return this.studentName;
}
public void setStudentName(String studentName) {
this.studentName = studentName;
}
public Set<Phone> getStudentPhoneNumbers() {
return this.studentPhoneNumbers;
}
public void setStudentPhoneNumbers(Set<Phone> studentPhoneNumbers) {
this.studentPhoneNumbers = studentPhoneNumbers;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + (int) (studentId ^ (studentId >>> 32));
result = prime * result + ((studentName == null) ? 0 : studentName.hashCode());
result = prime * result + ((studentPhoneNumbers == null) ? 0 : studentPhoneNumbers.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (getClass() != obj.getClass()) return false;
Student other = (Student) obj;
if (studentId != other.studentId) return false;
if (studentName == null) {
if (other.studentName != null) return false;
}
else if (!studentName.equals(other.studentName)) return false;
if (studentPhoneNumbers == null) {
if (other.studentPhoneNumbers != null) return false;
}
else if (!studentPhoneNumbers.equals(other.studentPhoneNumbers)) return false;
return true;
}
}
电话
package com.vaannila.student;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
@Entity
public class Phone {
@Id
@GeneratedValue
private long phoneId;
private String phoneType;
private String phoneNumber;
public Phone() {
}
public Phone(String phoneType, String phoneNumber) {
this.phoneType = phoneType;
this.phoneNumber = phoneNumber;
}
public long getPhoneId() {
return this.phoneId;
}
public void setPhoneId(long phoneId) {
this.phoneId = phoneId;
}
public String getPhoneType() {
return this.phoneType;
}
public void setPhoneType(String phoneType) {
this.phoneType = phoneType;
}
public String getPhoneNumber() {
return this.phoneNumber;
}
public void setPhoneNumber(String phoneNumber) {
this.phoneNumber = phoneNumber;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + (int) (phoneId ^ (phoneId >>> 32));
result = prime * result + ((phoneNumber == null) ? 0 : phoneNumber.hashCode());
result = prime * result + ((phoneType == null) ? 0 : phoneType.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null) return false;
if (getClass() != obj.getClass()) return false;
Phone other = (Phone) obj;
if (phoneId != other.phoneId) return false;
if (phoneNumber == null) {
if (other.phoneNumber != null) return false;
}
else if (!phoneNumber.equals(other.phoneNumber)) return false;
if (phoneType == null) {
if (other.phoneType != null) return false;
}
else if (!phoneType.equals(other.phoneType)) return false;
return true;
}
}
我在这里粘贴了整个代码，这样你就可以看到导入的来源。我认为问题就在那里。重要提示：我使用的JoinTable是 Hibernate Docs 推荐的
行！现在我用两个电话号码创建一个Student并将其正确保存在数据库中。这将创建以下内容：
学生
studentid | studentname
-----------+-------------
2 | foo
(1 rows)
学生电话
student_id | phone_id
------------+---------
2 | 3
2 | 4
(2 rows)
电话
phoneid | phonenumber | phonetyp
---------+-------------+---------
4 | 9889343423 | mobile
3 | 32354353 | house
(2 rows)
问题来了。如果我删除客户端中的一个电话号码（手机）并将分离的学生实体发送到服务器并执行更新，则休眠到以下内容：
Hibernate: update Student set studentName=? where studentId=?
Hibernate: update Phone set phoneNumber=?, phoneType=? where phoneId=?
Hibernate: delete from STUDENT_PHONE where STUDENT_ID=?
Hibernate: insert into STUDENT_PHONE (STUDENT_ID, PHONE_ID) values (?, ?)
如您所见，它只是删除了联接表中的条目，但并未删除电话表中的电话条目本身。所以现在表格看起来像这样：
学生
studentid | studentname
-----------+-------------
2 | foo
(1 rows)
学生电话
student_id | phone_id
------------+---------
2 | 3
(1 rows)
电话
phoneid | phonenumber | phonetyp
---------+-------------+---------
4 | 9889343423 | mobile
3 | 32354353 | house
(2 rows)
问题：这是正常行为吗？即使级联删除和孤立删除设置为真？我怎样才能实现休眠也删除电话表中的电话号码？
更新我正在使用 PostgreSQL