用的 是hibernate框架现在出了点问题

Question

代码先行
功能：加入一个sno=1 cno=1的数据到sc表中package stu.course.com;import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;/**
 *
 * @author Administrator
 */
@WebServlet(name = "XuankeServer", urlPatterns = {"/XuankeServer"})
public class XuankeServer extends HttpServlet {
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        Configuration cfg = new Configuration().configure();
        SessionFactory sf = cfg.buildSessionFactory();
        Session session = sf.openSession();
        Transaction ts = session.beginTransaction();
        
        SC sc=new SC();
        sc.setSno(1);
        sc.setCno(1);
        session.save(sc);
        ts.commit();
        session.close();
        
    }
}配置文件
1.hibernate.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>
    <!-- Database connection settings -->
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="connection.url">jdbc:mysql://localhost/ssc</property>
    <property name="connection.username">root</property>
    <property name="connection.password">111111</property>
    <property name="show_sql">true</property>
    <mapping resource="Student.hbm.xml"/>
   <mapping resource="sc.hbm.xml"/>
  </session-factory>
2.sc.hbm.xml
</hibernate-configuration>
<?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">
<hibernate-mapping>
  <class name="stu.course.com.SC" table="sc">
    <id name="sno">
      <generator class="native"/>
    </id>
    <property name="cno"/>
  </class>
</hibernate-mapping>
报错：
type Exception reportmessagedescription The server encountered an internal error () that prevented it from fulfilling this request.exceptionorg.hibernate.exception.GenericJDBCException: could not execute statement
org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:54)
org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:136)
org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:96)
org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:58)
org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2975)
org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3487)
org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:364)
org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:205)
org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:185)
org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:169)
org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:321)
org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:286)
org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:192)
org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:125)
org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
stu.course.com.XuankeServer.processRequest(XuankeServer.java:34)
stu.course.com.XuankeServer.doGet(XuankeServer.java:53)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root causejava.sql.SQLException: Field 'sno' doesn't have a default value
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2928)
com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1571)
com.mysql.jdbc.ServerPreparedStatement.serverExecute(ServerPreparedStatement.java:1124)
com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:676)
com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1166)
com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1082)
com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:1067)
org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:133)
org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:96)
org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:58)
org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2975)
org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3487)
org.hibernate.action.internal.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:81)
org.hibernate.engine.spi.ActionQueue.execute(ActionQueue.java:364)
org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction(ActionQueue.java:205)
org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:185)
org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:169)
org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:321)
org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:286)
org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:192)
org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:125)
org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
stu.course.com.XuankeServer.processRequest(XuankeServer.java:34)
stu.course.com.XuankeServer.doGet(XuankeServer.java:53)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.21 logs.求解答谢谢各位了！！HibernateJava异常

Answer 1

Field 'sno' doesn't have a default value sno 没有默认值，也就是你的sc.setSno(1);这个可以去掉

Answer 2

一般我看的都是配置datasource写sql，这个东西不怎么熟悉，学习了。

Answer 3

你的sno设置了native，就是交由数据库管理，你可以在数据库放将其设置为自动增长，然后你的项目就不需要设置sno的值，直接添加cno就可以了

Answer 4

native主键生成策略是让hibernate选择一种自增长方式，如果是oracle，就是sequence，如果是sqlserver，就是identity。。如果你要自己设置主键的话，就得改assigned

Answer 5

    <id name="sno">      <generator class="native"/>    </id>是这样配的吗?改为assigned 就可以手动指定.native 会使hibernate 根据数据库生成策略去指定的,跟你有没有set这个值没有关系.

Answer 6

谢谢  成功了！ 昨天搞了两个小时都没搞定原来是这个原因 吧native参数改成assigned就行了。结贴了分已送达？