尝试使用 SQLight Hybernate 运行简单的 java 项目。遇到异常:
Deleting Doc
Hibernate: delete from Doc
Updating document, DocID = 2, Name = doc 2
Hibernate: update Doc set DocName=?, Job=? where Id=?
exception Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
Jun 15, 2016 3:30:03 PM org.hibernate.event.def.AbstractFlushingEventListener performExecutions
SEVERE: 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.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:47)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2574)
at org.hibernate.persister.entity.AbstractEntityPersister.updateOrInsert(AbstractEntityPersister.java:2478)
at org.hibernate.persister.entity.AbstractEntityPersister.update(AbstractEntityPersister.java:2805)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:114)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:267)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:259)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:179)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1206)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:375)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:137)
at hyberntst.Db2.close(Db2.java:46)
at hyberntst.Db2.saveDoc(Db2.java:75)
at hyberntst.HybernTst.main(HybernTst.java:19)
我在data.db
中有空表文档
CREATE TABLE `Doc` (
`Id` INTEGER PRIMARY KEY AUTOINCREMENT,
`DocName` TEXT,
`Job` TEXT
)
Hybernate 配置 - hybernate.cfg.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">hyberntst.SQLiteDialect</property>
<property name="hibernate.connection.driver_class">org.sqlite.JDBC</property>
<property name="hibernate.connection.url">jdbc:sqlite:data.db</property>
<property name="hibernate.connection.pool_size">1</property>
<property name="hibernate.show_sql">true</property>
<!--property name="hibernate.current_session_context_class">thread</property-->
<!--property name="hibernate.query.factory_class">org.hibernate.hql.classic.ClassicQueryTranslatorFactory</property-->
<property name="hibernate.cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<mapping resource="hyberntst/Doc.hbm.xml"/>
</session-factory>
</hibernate-configuration>
负责处理DB的类:
package hyberntst;
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class Db2 {
private SessionFactory sessionFactory;
private Session session;
Db2() {
sessionFactory = new Configuration().configure().buildSessionFactory();
}
//------------------------------------------------------------------------------------------------------------------
private void open() {
session = sessionFactory.openSession();
session.beginTransaction();
}
private List query(String hql) {
Query query = session.createQuery(hql);
return query.list();
}
private void executeUpdate(String hql) {
Query query = session.createQuery(hql);
query.executeUpdate();
}
private void close() {
session.getTransaction().commit();
session.close();
}
public void deleteDoc() {
try {
open();
log.finer("Deleting Doc");
executeUpdate("delete Doc");
close();
} catch (Exception ex) {
log.logExept(ex);
} catch (Error err) {
log.warning(err.toString());
}
}
public void saveDoc(Doc doc) {
try {
open();
log.finer("Updating document, DocID = " + doc.getId() + ", Name = " + doc.getDocName());
session.saveOrUpdate(doc);
close();
} catch (Exception ex) {
log.logExept(ex);
}
}
}
用于写入数据库的文档类:
public class Doc {
private Integer id;
public Integer getId()
{
return this.id;
}
public void setId(Integer id)
{
this.id = id;
}
private String docName;
public String getDocName()
{
return this.docName;
}
public void setDocName(String docName)
{
this.docName = docName;
}
private String job;
public String getJob()
{
return this.docName;
}
public void setJob(String job)
{
this.job = job;
}
}
“主要”代码:
Doc d = new Doc();
d.setId(new Integer(2));
d.setDocName("doc 2");
d.setJob("job 2");
Db2 db2 = new Db2();
db2.deleteDoc();
db2.saveDoc(d);
在那里你可以看到我使用的库:
看起来从数据库中删除工作正常,但是插入有什么问题吗?
日志文件中的问号 parmas 是什么?
Hibernate: update Doc set DocName=?, Job=? where Id=?
最佳答案
一般情况下,如果entity id不为null,hibernate就会执行更新。 更多信息here :
saveOrUpdate() does the following:
- if the object is already persistent in this session, do nothing if another object associated with the session has the same identifier, throw an exception
- if the object has no identifier property, save() it
- if the object's identifier has the value assigned to a newly instantiated object, save() it
- if the object is versioned by a or , and the version property value is the same value assigned to a newly instantiated object, save() it
- otherwise update() the object
您必须显式调用 save()
或将 id
保留为空
关于java - Hello World hibernate ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37854121/