[英]JPA/Hibernate Composite Primary Foriegn Key ManyToOne Mapping
*** Solved - Updated w/ the Resolution* ** *** 解决-更新了分辨率* **
I have two tables: 我有两个表:
notification - composite key made of UserId + NotificationDetail notification-由UserId + NotificationDetail组成的复合键
notification_detail - single primary key notification_detail-单主键
I want to use JPA to persist and read these objects but cannot get the ManyToOne mapping to work. 我想使用JPA保留并读取这些对象,但是无法使ManyToOne映射起作用。
Many notification map to one notification_detail . 许多通知映射到一个notification_detail 。
Tables: 表格:
create table notification(
notification_user_id int not null,
notification_detail_id int not null,
notification_status_cd int not null,
primary key(notification_user_id, notification_detail_id),
constraint pkey_notification_detail foreign key(notification_detail_id) references notification_detail(notification_detail_id),
constraint pkey_notification_status_cd foreign key(notification_status_cd) references lk_notification_status(notification_status_id)
);
create table notification_detail (
notification_detail_id int auto_increment,
notification_type_cd int not null,
notification_message varchar(50) not null,
primary key(notification_detail_id),
constraint pkey_notification_type_cd foreign key(notification_type_cd) references lk_notification_type(notification_type_id)
);
*** Resolved and Correct JPA Setup: * ** *** 已解决和正确的JPA设置: * **
class NotificationId implements Serializable {
private static final long serialVersionUID = 1L;
Integer notificationUserId;
Integer details;
public Integer getNotificationUserId() {
return notificationUserId;
}
public void setNotificationUserId(Integer notificationUserId) {
this.notificationUserId = notificationUserId;
}
public Integer getDetails() {
return details;
}
public void setDetails(Integer details) {
this.details = details;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((details == null) ? 0 : details.hashCode());
result = prime * result + ((notificationUserId == null) ? 0 : notificationUserId.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;
NotificationId other = (NotificationId) obj;
if (details == null) {
if (other.details != null)
return false;
} else if (!details.equals(other.details))
return false;
if (notificationUserId == null) {
if (other.notificationUserId != null)
return false;
} else if (!notificationUserId.equals(other.notificationUserId))
return false;
return true;
}
}
@Entity
@Table(name="notification")
@IdClass(NotificationId.class)
public class Notification implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@NotNull
private Integer notificationUserId;
@Id
@NotNull
@ManyToOne(fetch=FetchType.LAZY, cascade=CascadeType.ALL)
@JoinColumn(name="notification_detail_id")
private NotificationDetail details;
@NotNull
private Integer notificationStatusCd;
@NotNull
private Integer updateUserId;
public Integer getNotificationUserId() {
return notificationUserId;
}
public void setNotificationUserId(Integer notificationUserId) {
this.notificationUserId = notificationUserId;
}
public NotificationDetail getDetails() {
return details;
}
public void setDetails(NotificationDetail details) {
this.details = details;
}
public Integer getNotificationStatusCd() {
return notificationStatusCd;
}
public void setNotificationStatusCd(Integer notificationStatusCd) {
this.notificationStatusCd = notificationStatusCd;
}
public Integer getUpdateUserId() {
return updateUserId;
}
public void setUpdateUserId(Integer updateUserId) {
this.updateUserId = updateUserId;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((details == null) ? 0 : details.hashCode());
result = prime * result + ((notificationStatusCd == null) ? 0 : notificationStatusCd.hashCode());
result = prime * result + ((notificationUserId == null) ? 0 : notificationUserId.hashCode());
result = prime * result + ((updateUserId == null) ? 0 : updateUserId.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;
Notification other = (Notification) obj;
if (details == null) {
if (other.details != null)
return false;
} else if (!details.equals(other.details))
return false;
if (notificationStatusCd == null) {
if (other.notificationStatusCd != null)
return false;
} else if (!notificationStatusCd.equals(other.notificationStatusCd))
return false;
if (notificationUserId == null) {
if (other.notificationUserId != null)
return false;
} else if (!notificationUserId.equals(other.notificationUserId))
return false;
if (updateUserId == null) {
if (other.updateUserId != null)
return false;
} else if (!updateUserId.equals(other.updateUserId))
return false;
return true;
}
}
@Entity
@Table(name="notification_detail")
public class NotificationDetail implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Integer notificationDetailId;
@NotNull
private Integer notificationTypeCd;
@NotNull
private String notificationMessage;
@OneToMany(fetch=FetchType.LAZY, cascade=CascadeType.ALL, mappedBy="details")
private Set<Notification> notifications;
@NotNull
private Integer updateUserId;
public Integer getNotificationDetailId() {
return notificationDetailId;
}
public void setNotificationDetailId(Integer notificationDetailId) {
this.notificationDetailId = notificationDetailId;
}
public Integer getNotificationTypeCd() {
return notificationTypeCd;
}
public void setNotificationTypeCd(Integer notificationTypeCd) {
this.notificationTypeCd = notificationTypeCd;
}
public String getNotificationMessage() {
return notificationMessage;
}
public void setNotificationMessage(String notificationMessage) {
this.notificationMessage = notificationMessage;
}
public Set<Notification> getNotifications() {
return notifications;
}
public void setNotifications(Set<Notification> notifications) {
this.notifications = notifications;
}
public void addNotification(Notification notification){
if(notifications == null)
notifications = new HashSet<Notification>();
notifications.add(notification);
}
public Integer getUpdateUserId() {
return updateUserId;
}
public void setUpdateUserId(Integer updateUserId) {
this.updateUserId = updateUserId;
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((notificationDetailId == null) ? 0 : notificationDetailId.hashCode());
result = prime * result + ((notificationMessage == null) ? 0 : notificationMessage.hashCode());
result = prime * result + ((notificationTypeCd == null) ? 0 : notificationTypeCd.hashCode());
result = prime * result + ((notifications == null) ? 0 : notifications.hashCode());
result = prime * result + ((updateUserId == null) ? 0 : updateUserId.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;
NotificationDetail other = (NotificationDetail) obj;
if (notificationDetailId == null) {
if (other.notificationDetailId != null)
return false;
} else if (!notificationDetailId.equals(other.notificationDetailId))
return false;
if (notificationMessage == null) {
if (other.notificationMessage != null)
return false;
} else if (!notificationMessage.equals(other.notificationMessage))
return false;
if (notificationTypeCd == null) {
if (other.notificationTypeCd != null)
return false;
} else if (!notificationTypeCd.equals(other.notificationTypeCd))
return false;
if (notifications == null) {
if (other.notifications != null)
return false;
} else if (!notifications.equals(other.notifications))
return false;
if (updateUserId == null) {
if (other.updateUserId != null)
return false;
} else if (!updateUserId.equals(other.updateUserId))
return false;
return true;
}
}
JPA Usage: JPA用法:
NotificationDetail details = new NotificationDetail();
details.setMessage("Hello");
details.setTypeCd(NotificationTypeEnum.INFO);
detail.setUpdateUserId(userId);
Notification notif = new Notification();
notif.setNotifiedUserId(userId);
notif.setStatusCd(NotificationStatusEnum.UNREAD);
notif.setDetails(details);
notificationRepository.save(notif);
*** This error is now resolved * **: *** 现在已解决此错误 * **:
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'notificati0_.details_notificationDetailId' in 'field list'
*** Original Problem: * ** *** 原始问题: * **
I've tried all types of different configurations. 我尝试了所有类型的不同配置。 The best I can come up with is that my situation is complicated because the parent object "notification" has a composite key "notification_detail_id" that is the primary key of the child as well.
我能想到的最好的事情是我的情况很复杂,因为父对象“ notification”有一个复合键“ notification_detail_id”,它也是孩子的主键。 This makes it's very difficult for Hibernate to persist the child first, then take the key and save it for the parent.
这使得Hibernate很难先持久保留子项,然后再获取密钥并将其保存给父项。
I realize my annotations are incorrect somewhere but just can't figure it out. 我意识到我的注释在某处不正确,但无法弄清楚。
It looks like you are dealing with a "derived identity". 看起来您正在处理“派生身份”。 Change your classes to look like this:
更改类,使其看起来像这样:
class NotificationId implements Serializable {
private static final long serialVersionUID = 1L;
Integer notifiedUserId;
Integer details;
...
}
@Entity
@IdClass(NotificationId.class)
@Table(name="notification")
public class Notification implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@NotNull
@Column(name="notification_user_id")
private Integer notifiedUserId;
@Id
@NotNull
@ManyToOne(fetch=FetchType.LAZY, cascade=CascadeType.ALL)
@JoinColumn(name="notification_detail_id")
private NotificationDetail details;
@NotNull
@Column(name="notification_status_cd")
private Integer statusCd;
@Column(name="update_timestamp")
private Date timestamp;
...
}
NB: 注意:
NotificationId.notificationDetailId
has been renamed to details
to match the corresponding field in Notification
NotificationId.notificationDetailId
已重命名为details
以匹配Notification
中的相应字段 Notification.notificationDetailId
has been removed Notification.notificationDetailId
已被删除 Notification.details
has been marked as an @Id
Notification.details
已被标记为@Id
Your field model seems to imply you should do the same thing with the relation between Notification
and User
. 您的字段模型似乎暗示您应该对
Notification
和User
之间的关系执行相同的User
。
Derived identities are discussed in the JPA 2.1 spec, section 2.4.1. JPA 2.1规范的第2.4.1节中讨论了派生身份。
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