hibernate程序中的异常

我遵循一个基本的hibernate教程。教程程序正在运行&如教程中所述显示输出，但在输出后显示异常。该程序在两个MySql数据库中写入、检索和删除值。
例外情况如下：

29088 [main] ERROR org.hibernate.jdbc.AbstractBatcher - Exception executing batch: 
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:85)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:70)
    at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:90)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:172)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
    at com.hib.Test.deleteUser(Test.java:187)
    at com.hib.Test.main(Test.java:55)
Hibernate: delete from users where id=?
29093 [main] ERROR org.hibernate.event.def.AbstractFlushingEventListener - Could not synchronize database state with session
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:85)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:70)
    at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:90)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:172)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
    at com.hib.Test.deleteUser(Test.java:187)
    at com.hib.Test.main(Test.java:55)
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
    at org.hibernate.jdbc.Expectations$BasicExpectation.checkBatched(Expectations.java:85)
    at org.hibernate.jdbc.Expectations$BasicExpectation.verifyOutcome(Expectations.java:70)
    at org.hibernate.jdbc.BatchingBatcher.checkRowCounts(BatchingBatcher.java:90)
    at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
    at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:172)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
    at com.hib.Test.deleteUser(Test.java:187)
    at com.hib.Test.main(Test.java:55)

这是主程序

package com.hib;

import java.util.Iterator;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.Transaction;

public class Test {

 /**
  * @param args
  */
 public static void main(String[] args) {

  Test tst = new Test();

  /**
   * adding records
   */
  tst.addUser("Saranga", "Rath");
  tst.addUser("Isuru", "Sampath");
  tst.addUser("Saranga", "Jaya");
  tst.addUser("Prasanna", "Milinda");

  tst.addTask(1, "Call", "Call Pubudu at 5 PM");
  tst.addTask(1, "Shopping", "Buy some foods for Kity");
  tst.addTask(2, "Email", "Send birthday wish to Pubudu");
  tst.addTask(2, "SMS", "Send message to Dad");
  tst.addTask(2, "Office", "Give a call to Boss");

  /**
   *  retrieving data
   */
  tst.getFullName("Saranga");

  /**
   * full updating records
   */
  User user = new User();
  user.setId(1);
  user.setFirstName("Saranga");
  user.setLastName("Rathnayake");
  tst.updateUser(user);

  /**
   * partial updating records
   */
  tst.updateLastName(3, "Jayamaha");

  /**
   * deleting records
   */
  User user1 = new User();
  user1.setId(4);
  tst.deleteUser(user1);
 }

 private void addUser(String firstName, String lastName) {

  Transaction trns = null;
  Session session = HibernateUtil.getSessionFactory().openSession();
  try {
   trns = session.beginTransaction();

   User user = new User();

   user.setFirstName(firstName);
   user.setLastName(lastName);

   session.save(user);

   session.getTransaction().commit();
  } catch (RuntimeException e) {
   if(trns != null){
    trns.rollback();
   }
   e.printStackTrace();
  } finally{
   session.flush();
   session.close();
  }
 }

 private void addTask(int userID, String title, String description) {

  Transaction trns = null;
  Session session = HibernateUtil.getSessionFactory().openSession();
  try {
   trns = session.beginTransaction();

   Task task = new Task();

   task.setUserID(userID);
   task.setTitle(title);
   task.setDescription(description);

   session.save(task);

   session.getTransaction().commit();
  } catch (RuntimeException e) {
   if(trns != null){
    trns.rollback();
   }
   e.printStackTrace();
  } finally{
   session.flush();
   session.close();
  }
 }

 private void updateLastName(int id, String lastName) {
  Transaction trns = null;
  Session session = HibernateUtil.getSessionFactory().openSession();
  try {
   trns = session.beginTransaction();
   String hqlUpdate = "update User u set u.lastName = :newLastName where u.id = :oldId";
   int updatedEntities = session.createQuery( hqlUpdate )
   .setString( "newLastName", lastName )
   .setInteger( "oldId", id )
   .executeUpdate();

   trns.commit();
  } catch (RuntimeException e) {
   if(trns != null){
    trns.rollback();
   }
   e.printStackTrace();
  } finally{
   session.flush();
   session.close();
  }

 }

 private void updateUser(User user) {
  Transaction trns = null;
  Session session = HibernateUtil.getSessionFactory().openSession();
  try {
   trns = session.beginTransaction();

   session.update(user);

   session.getTransaction().commit();
  } catch (RuntimeException e) {
   if(trns != null){
    trns.rollback();
   }
   e.printStackTrace();
  } finally{
   session.flush();
   session.close();
  }
 }

 private void getFullName(String firstName) {
  Transaction trns = null;
  Session session = HibernateUtil.getSessionFactory().openSession();
  try {
   trns = session.beginTransaction();
   List<User> users = session.createQuery("from User as u where u.firstName = :firstName")
   .setString( "firstName", firstName )
   .list();
   for (Iterator<User> iter = users.iterator(); iter.hasNext();) {
    User user = iter.next();
    System.out.println(user.getFirstName() +" " + user.getLastName());
   }
   trns.commit();
  } catch (RuntimeException e) {
   if(trns != null){
    trns.rollback();
   }
   e.printStackTrace();
  } finally{
   session.flush();
   session.close();
  }
 }

 private void deleteUser(User user) {
  Transaction trns = null;
  Session session = HibernateUtil.getSessionFactory().openSession();
  try {
   trns = session.beginTransaction();

   session.delete(user);

   session.getTransaction().commit();
  } catch (RuntimeException e) {
   if(trns != null){
    trns.rollback();
   }
   e.printStackTrace();
  } finally{
   session.flush();
   session.close();
  }
 }
}

User.java

package com.hib;

public class User {
 private Integer id;
 private String firstName;
 private String lastName;

 public Integer getId() {
  return id;
 }
 public void setId(Integer id) {
  this.id = id;
 }
 public String getFirstName() {
  return firstName;
 }
 public void setFirstName(String firstName) {
  this.firstName = firstName;
 }
 public String getLastName() {
  return lastName;
 }
 public void setLastName(String lastName) {
  this.lastName = lastName;
 }
}

Task.java

package com.hib;

public class Task {

 private Integer id;
 private Integer userID;
 private String title;
 private String description;

 public Integer getId() {
  return id;
 }
 public void setId(Integer id) {
  this.id = id;
 }
 public Integer getUserID() {
  return userID;
 }
 public void setUserID(Integer userID) {
  this.userID = userID;
 }
 public String getTitle() {
  return title;
 }
 public void setTitle(String title) {
  this.title = title;
 }
 public String getDescription() {
  return description;
 }
 public void setDescription(String description) {
  this.description = description;
 }
}

---

如果尝试删除或更新不存在的行，则会发生此异常。 这正是你要做的：

User user1 = new User();
user1.setId(4);
tst.deleteUser(user1);

user1从未被持久化到DB，那么hibernate应该如何删除它呢

顺便说一句：不要自己设置一个实体的自动生成PK值，这意味着麻烦。 另外，我注意到您通过在任务中使用userID本身引用任务中的用户。如果您希望分离域，则可以使用业务密钥（例如，唯一用户电子邮件等）以这种方式进行关联，但如果您使用的是主键，则这种关联没有意义。在任务中使用

User-User

而不是

Integer-userID

，并使用User创建一个

manytone

User user1 = new User();
user1.setId(4);
tst.deleteUser(user1);