myeclipse连接mysql数据库，hibernate出错？
出错：严重: Servlet.service() for servlet action threw exception
java.sql.SQLException: Unknown column 'this_.id' in 'field list'
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2901)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1584)
at com.mysql.jdbc.Connection.serverPrepare(Connection.java:4932)
at com.mysql.jdbc.Connection.prepareStatement(Connection.java:1312)
at com.mysql.jdbc.Connection.prepareStatement(Connection.java:1284)
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:534)
at org.hibernate.jdbc.AbstractBatcher.getPreparedStatement(AbstractBatcher.java:452)
at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1577)
at org.hibernate.loader.Loader.doQuery(Loader.java:696)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
at org.hibernate.loader.Loader.doList(Loader.java:2232)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2129)
at org.hibernate.loader.Loader.list(Loader.java:2124)
at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1597)
at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
at com.qdu.sun.hibernate.UserDAO.findByExample(UserDAO.java:67)
at com.qdu.sun.BO.LoginBO.validate(LoginBO.java:20)
at com.qdu.sun.struts.action.LoginAction.execute(LoginAction.java:43)
at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.qdu.sun.BO.FormFilter.doFilter(FormFilter.java:75)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
at java.lang.Thread.run(Thread.java:619)
Hibernate: select this_.id as id0_0_, this_.username as username0_0_, this_.password as password0_0_ from user this_ where (this_.username=? and this_.password=?)
Hibernate: select this_.id as id0_0_, this_.username as username0_0_, this_.password as password0_0_ from user this_ where (this_.username=? and this_.password=?)
Hibernate: select this_.id as id0_0_, this_.username as username0_0_, this_.password as password0_0_ from user this_ where (this_.username=? and this_.password=?)
Hibernate: select this_.id as id0_0_, this_.username as username0_0_, this_.password as password0_0_ from user this_ where (this_.username=? and this_.password=?)
代码：
LoginBO.java
package com.qdu.sun.BO;
import java.sql.*;
import java.util.List;
import org.hibernate.Transaction;
import com.qdu.sun.hibernate.*;
public class LoginBO {
public boolean validate(String username, String password) {
// 实例化 DAO
UserDAO dao = new UserDAO();
// 打开事务
Transaction tran = dao.getSession().beginTransaction();
// 生成持久化对象
User user = new User();
user.setUsername(username);
user.setPassword(password);
List list = dao.findByExample(user);
tran.commit();
if (list.size() > 0) {
return true;
} else {
return false;
}
}
}
HibernateSessionFactory.java
package com.qdu.sun.hibernate;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
/**
* Configures and provides access to Hibernate sessions, tied to the
* current thread of execution. Follows the Thread Local Session
* pattern, see {@link http://hibernate.org/42.html }.
*/
public class HibernateSessionFactory {
/**
* Location of hibernate.cfg.xml file.
* Location should be on the classpath as Hibernate uses
* #resourceAsStream style lookup for its configuration file.
* The default classpath location of the hibernate config file is
* in the default package. Use #setConfigFile() to update
* the location of the configuration file for the current session.
*/
private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
private static Configuration configuration = new Configuration();
private static org.hibernate.SessionFactory sessionFactory;
private static String configFile = CONFIG_FILE_LOCATION;
static {
try {
configuration.configure(configFile);
sessionFactory = configuration.buildSessionFactory();
} catch (Exception e) {
System.err
.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}
private HibernateSessionFactory() {
}
/**
* Returns the ThreadLocal Session instance. Lazy initialize
* the <code>SessionFactory</code> if needed.
*
* @return Session
* @throws HibernateException
*/
public static Session getSession() throws HibernateException {
Session session = (Session) threadLocal.get();
if (session == null || !session.isOpen()) {
if (sessionFactory == null) {
rebuildSessionFactory();
}
session = (sessionFactory != null) ? sessionFactory.openSession()
: null;
threadLocal.set(session);
}
return session;
}
/**
* Rebuild hibernate session factory
*
*/
public static void rebuildSessionFactory() {
try {
configuration.configure(configFile);
sessionFactory = configuration.buildSessionFactory();
} catch (Exception e) {
System.err
.println("%%%% Error Creating SessionFactory %%%%");
e.printStackTrace();
}
}
/**
* Close the single hibernate session instance.
*
* @throws HibernateException
*/
public static void closeSession() throws HibernateException {
Session session = (Session) threadLocal.get();
threadLocal.set(null);
if (session != null) {
session.close();
}
}
/**
* return session factory
*
*/
public static org.hibernate.SessionFactory getSessionFactory() {
return sessionFactory;
}
/**
* return session factory
*
* session factory will be rebuilded in the next call
*/
public static void setConfigFile(String configFile) {
HibernateSessionFactory.configFile = configFile;
sessionFactory = null;
}
/**
* return hibernate configuration
*
*/
public static Configuration getConfiguration() {
return configuration;
}
}
User.java
package com.qdu.sun.hibernate;
/**
* User entity.
*
* @author MyEclipse Persistence Tools
*/
public class User implements java.io.Serializable {
// Fields
private Integer id;
private String username;
private String password;
// Constructors
/** default constructor */
public User() {
}
/** full constructor */
public User(String username, String password) {
this.username = username;
this.password = password;
}
// Property accessors
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
}
User.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="com.qdu.sun.hibernate.User" table="user" >
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="increment" />
</id>
<property name="username" type="java.lang.String">
<column name="username" length="20" not-null="true" />
</property>
<property name="password" type="java.lang.String">
<column name="password" length="20" not-null="true" />
</property>
</class>
</hibernate-mapping>
数据库截图：
MySQL Hibernate MyEclipse --------------------编程问答-------------------- findByExample这个函数也看看 --------------------编程问答-------------------- java.sql.SQLException: Unknown column 'this_.id' in 'field list'
这个列不存在this_.id --------------------编程问答-------------------- 为什么？？？ Unknown column 'this_.id' in 'field list'
findByExample这个函数没问题吧
--------------------编程问答-------------------- user.setPassword(password);
List list = dao.findByExample(user);//这时候数据库应该不存在user表，因为事务还没有提交。报这个错误很正常。
tran.commit();
比较表名大小写，字段名大小写是否都正确。 --------------------编程问答-------------------- 检查user表没错啊，我之前觉得是属性id这里出错了，重新设置成自动生成的也还是错的
--------------------编程问答--------------------
解决了这个问题了，不过页面跳转的时候出错了。
--------------------编程问答--------------------
纠结了那么久，我终于成功了，我做出来了！然后谢谢各位帮我这只菜鸟这么多
--------------------编程问答--------------------
-----问题原因？
--------------------编程问答--------------------
有两个问题：（1）struts-config.xmlz中添加Forward时把fail.jsp写成了failed.jsp （2）没有在MySQL中插入记录，就不能登录--------------------编程问答--------------------
如果User表存在，仅仅只是没有数据的话，就报Unknown column 'this_.id' in 'field list'不合逻辑啊，如果表中该column不存在，报Unknown column才合逻辑 --------------------编程问答-------------------- 页面不对，会包404错误，没值会包空指针，你这都不相关。
补充：Java , Eclipse
