hibernate向mysql插入数据，插入成功但查询时无法显示

yuzhisheng 2008-04-09 09:41:59

先描述下问题：
我在eclipse中配置好了连接mysql数据库，数据库名：webases,表名：admin;字段：id(auto-increment),name,password;并且通过jsp可以成功插入数据，假设此时id是1000，但用select * from admin;却无法查询出刚添加的数据，手动添加一条数据再select * from admin;查询出来的数据id是10001，这说明从jsp页面向mysql插入数据成功，但是为什么查询不出来呢，迷惑中，恳请各位大侠帮忙，感激不尽！！谢谢

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awusoft 2008-04-09

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public void save(Admin transientInstance) {
log.debug("saving Admin instance");
try {
getSession().save(transientInstance);
log.debug("save successful");
} catch (RuntimeException re) {
log.error("save failed", re);
throw re;
}
}

没有使用事务.....................

yuzhisheng 2008-04-09

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谢谢大家，问题解决了，是事务的问题，eclipse自动生成的代码中没有加入事务处理的代码，但还有点不明白，没用事务是不是不能提交数据到数据库了，但是数据库中id又会被占用。

yuzhisheng 2008-04-09

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我用的是jdbc驱动，添加数据时调用adminDAO.java中的save()方法
这是addminAction.java
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
AddAdminForm addAdminForm = (AddAdminForm) form;

// TODO Add a new admin
Admin admin = new Admin();
admin.setName(addAdminForm.getName ());
admin.setPassword(addAdminForm.getPassword ());
AdminDAO adminDAO = new AdminDAO ();
adminDAO.save(admin);

return mapping.findForward("success");
}
}

yuzhisheng 2008-04-09

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AWUSOFT,谢谢你，我加上去了还是不能查询出来，这是我配置连接mysql时自动生成的adminDAO.java类
package com.hibernate;

import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.LockMode;
import org.hibernate.Query;
import org.hibernate.criterion.Example;

/**
* Data access object (DAO) for domain model class Admin.
* @see com.hibernate.Admin
* @author MyEclipse - Hibernate Tools
*/
public class AdminDAO extends BaseHibernateDAO {

private static final Log log = LogFactory.getLog(AdminDAO.class);

//property constants
public static final String NAME = "name";
public static final String PASSWORD = "password";

public void save(Admin transientInstance) {
log.debug("saving Admin instance");
try {
getSession().save(transientInstance);
log.debug("save successful");
} catch (RuntimeException re) {
log.error("save failed", re);
throw re;
}
}

public void delete(Admin persistentInstance) {
log.debug("deleting Admin instance");
try {
getSession().delete(persistentInstance);
log.debug("delete successful");
} catch (RuntimeException re) {
log.error("delete failed", re);
throw re;
}
}

public Admin findById( java.lang.Long id) {
log.debug("getting Admin instance with id: " + id);
try {
Admin instance = (Admin) getSession()
.get("com.hibernate.Admin", id);
return instance;
} catch (RuntimeException re) {
log.error("get failed", re);
throw re;
}
}

public List findByExample(Admin instance) {
log.debug("finding Admin instance by example");
try {
List results = getSession()
.createCriteria("com.hibernate.Admin")
.add(Example.create(instance))
.list();
log.debug("find by example successful, result size: " + results.size());
return results;
} catch (RuntimeException re) {
log.error("find by example failed", re);
throw re;
}
}

public List findByProperty(String propertyName, Object value) {
log.debug("finding Admin instance with property: " + propertyName
+ ", value: " + value);
try {
String queryString = "from Admin as model where model."
+ propertyName + "= ?";
Query queryObject = getSession().createQuery(queryString);
queryObject.setParameter(0, value);
return queryObject.list();
} catch (RuntimeException re) {
log.error("find by property name failed", re);
throw re;
}
}

public List findByName(Object name) {
return findByProperty(NAME, name);
}

public List findByPassword(Object password) {
return findByProperty(PASSWORD, password);
}

public Admin merge(Admin detachedInstance) {
log.debug("merging Admin instance");
try {
Admin result = (Admin) getSession()
.merge(detachedInstance);
log.debug("merge successful");
return result;
} catch (RuntimeException re) {
log.error("merge failed", re);
throw re;
}
}

public void attachDirty(Admin instance) {
log.debug("attaching dirty Admin instance");
try {
getSession().saveOrUpdate(instance);
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
}

public void attachClean(Admin instance) {
log.debug("attaching clean Admin instance");
try {
getSession().lock(instance, LockMode.NONE);
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
}
}
再帮忙看下好吗，谢谢！！！

awusoft 2008-04-09

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如果你用hibernate添加,需要事务提交.
如果事务也提交了还不行的话加一行session.flush();//这个尽量不使用吧

<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<property name="hibernate.cache.use_second_level_cache">false</property>
配置文件加这两行关闭二级缓存.

还有每次用完了把session.close()一下

yuzhisheng 2008-04-09

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AWUSOFT ，你好，这应该怎样去解决呢，新手不懂，恳请帮忙

awusoft 2008-04-09

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Hibernate的缓存问题

yuzhisheng 2008-04-09

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我在jsp页面中添加一条数据，然后手动添加一条，用select * from admin;的结果是
+-----+------+----------+
| id | name | password |
+-----+------+----------+
| 114 | yu | yu |
| 115 | yuyu | yuyu |
| 117 | zhi | zhi |
+-----+------+----------+
3 rows in set (0.00 sec)
也就是从jsp添加进去的那条数据成功了，因为id 号已经自增到117了，但那条数据去哪了呢，为什么查询不出来呢

yuzhisheng 2008-04-09