Java Hibernate - 复合主键问题

Question

我有以下两张表

创建表 event_type_master ( Event_Type_Code varchar(128) NOT NULL, 主键（Event_Type_Code） )

创建表 event_master ( Event_Code varchar(128) NOT NULL, Event_Type_Code varchar(128) NOT NULL, 主键 (Event_Code,Event_Type_Code), 约束 FK1 外键 (Event_Type_Code) 参考 event_type_master (Event_Type_Code) )

现在我已经为上述关系创建了模型类，如下所示 EventMaster 类：-

@Entity
@Table(name="event_master")
public class EventMaster  implements java.io.Serializable {

 private EventMasterId id;
 private EventTypeMaster eventTypeMaster;
 private String eventName;

public EventMaster() {
}

public EventMaster(EventMasterId id, EventTypeMaster eventTypeMaster) {
    this.id = id;
    this.eventTypeMaster = eventTypeMaster;
}
public EventMaster(EventMasterId id, EventTypeMaster eventTypeMaster) {
   this.id = id;
   this.eventTypeMaster = eventTypeMaster;
   this.eventName = eventName;
}

@EmbeddedId    
@AttributeOverrides( {
@AttributeOverride(name="eventCode", column=@Column(name="Event_Code", nullable=false, length=128) ), 
@AttributeOverride(name="eventTypeCode", column=@Column(name="Event_Type_Code", nullable=false, length=128) ) } )
public EventMasterId getId() {
    return this.id;
}

public void setId(EventMasterId id) {
    this.id = id;
}

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="Event_Type_Code",referencedColumnName = "Event_Type_Code",  nullable=false, insertable=false, updatable=false)
public EventTypeMaster getEventTypeMaster()
{
    return this.eventTypeMaster;
}

public void setEventTypeMaster(EventTypeMaster eventTypeMaster) {
    this.eventTypeMaster = eventTypeMaster;
}

}

复合主键设置的 EventMasterId 类：-

@Embeddable
public class EventMasterId  implements java.io.Serializable {
private String eventCode;
private String eventTypeCode;

public EventMasterId() {
}

public EventMasterId(String eventCode, String eventTypeCode) 
{
   this.eventCode = eventCode;
   this.eventTypeCode = eventTypeCode;
}

@Column(name="Event_Code", nullable=false, length=128)
public String getEventCode() {
    return this.eventCode;
}

public void setEventCode(String eventCode) {
    this.eventCode = eventCode;
}

@Column(name="Event_Type_Code", nullable=false, length=128)
public String getEventTypeCode() {
    return this.eventTypeCode;
}

public void setEventTypeCode(String eventTypeCode) {
    this.eventTypeCode = eventTypeCode;
}

公共布尔等于（对象其他）{ ........... }

公共 int hashCode() { ………… }
}

EventTypeMaster 类

@Entity
@Table(name="event_type_master")
public class EventTypeMaster  implements java.io.Serializable {
 private String eventTypeCode;
 private String eventTypeName;
 private Set<EventMaster> eventMasters = new HashSet<EventMaster>(0);

public EventTypeMaster() {
}


public EventTypeMaster(String eventTypeCode) {
    this.eventTypeCode = eventTypeCode;
}
public EventTypeMaster(String eventTypeCode, String eventTypeName, Set eventMasters) {
   this.eventTypeCode = eventTypeCode;
   this.eventTypeName = eventTypeName;
   this.eventMasters = eventMasters;
}

@Id    
@Column(name="Event_Type_Code", unique=true, nullable=false, length=128)
public String getEventTypeCode() {
    return this.eventTypeCode;
}

public void setEventTypeCode(String eventTypeCode) {
    this.eventTypeCode = eventTypeCode;
}

@OneToMany(cascade=CascadeType.ALL, fetch=FetchType.LAZY, mappedBy="eventTypeMaster")
@JoinColumn(name="Event_Type_Code", referencedColumnName = "Event_Type_Code")
public Set<EventMaster> getEventMasters() {
    return this.eventMasters;
}

public void setEventMasters(Set<EventMaster> eventMasters) {
    this.eventMasters = eventMasters;
}

}

设置完所有后，我使用 Netbeans 创建了一个 HebernateUtil 类以连接到 HibernateSession Factory，并尝试测试将记录添加到 event_master 表，如下所示

    Session session = null;
    session = NewHibernateUtil.getSessionFactory().getCurrentSession();

    try {
        org.hibernate.Transaction tx = session.beginTransaction(); 
        EventMasterId key1=new EventMasterId();
        EventTypeMaster eTypeMaster1=new EventTypeMaster();

        eTypeMaster1=(EventTypeMaster)session.load(EventTypeMaster.class, "e1");

        key1.setEventCode(eTypeMaster1.getEventTypeCode());
        key1.setEventCode("Test_Event_Code");

        EventMaster em=new EventMaster();
        em.setId(key1);
        em.setEventTypeMaster(eTypeMaster1);
        em.setEventDesc("Event Description");


        session.save(em);

        session.getTransaction().commit();

    } catch (Exception e) {
        e.printStackTrace();
    }

但我得到以下错误

休眠：插入 event_master（Create_DTTM、Created_By、Event_Desc、Event_Name、Event_Short_Name、Last_Mod_By、Last_Mod_DTTM、Event_Code、Event_Type_Code）值（?、?、?、?、?、?、?、?、?） 1473 [main] WARN org.hibernate.util.JDBCExceptionReporter - SQL 错误：1048，SQLState：23000 1473 [main] 错误 org.hibernate.util.JDBCExceptionReporter - 列 'Event_Type_Code' 不能为空 1474 [main] 错误 org.hibernate.event.def.AbstractFlushingEventListener - 无法将数据库状态与会话同步 org.hibernate.exception.ConstraintViolationException：无法执行 JDBC 批量更新 org.hibernate.exception.ConstraintViolationException：无法执行 JDBC 批量更新 在 org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94) 在 org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) 在 org.hibernate.jdbc.AbstractBatcher.executeBatch（AbstractBatcher.java:275） 在 org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266) 在 org.hibernate.engine.ActionQueue.executeActions（ActionQueue.java:167） 在 org.hibernate.event.def.AbstractFlushingEventListener.performExecutions（AbstractFlushingEventListener.java:321） 在 org.hibernate.event.def.DefaultFlushEventListener.onFlush（DefaultFlushEventListener.java:50） 在 org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1028) 在 org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:366) 在 org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137) 在 test.NewMain.main(NewMain.java:46) 原因：java.sql.BatchUpdateException：列 'Event_Type_Code' 不能为空 在 com.mysql.jdbc.PreparedStatement.executeBatchSerially（PreparedStatement.java:1666） 在 com.mysql.jdbc.PreparedStatement.executeBatch（PreparedStatement.java:1082） 在 org.hibernate.jdbc.BatchingBatcher.doExecuteBatch（BatchingBatcher.java:70） 在 org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)

请帮我解决这个问题。

Answer 1

我认为你有一个错字。

key1.setEventCode(eTypeMaster1.getEventTypeCode());
key1.setEventCode("Test_Event_Code");

第一行应该是 key1.setEventTypeCode。