package com.jxq.test;
import java.util.Iterator;
import java.util.List;
import org.hibernate.Session;
import org.junit.Test;
import com.jxq.common.HibernateUtils;
import com.jxq.model.User;
public class test01 {
@Test
public void aa(){
System.out.println("jalsdjflajsdfl;a");
Session ss=null;
try {
ss=HibernateUtils.openSession();
ss.beginTransaction();
User u=new User();
u.setUsername("ljlj");
u.setUserpass("123");
u.setNickname("捡垃圾");
u.setEmail("[email protected]");
ss.save(u);
ss.getTransaction().commit();
} catch (Exception e) {
e.printStackTrace();
ss.getTransaction().rollback();
}finally{
if(ss!=null) ss.close();
}
}
@Test
public void bb(){
System.out.println("jalsdjflajsdfl;a");
Session ss=null;
try {
ss=HibernateUtils.openSession();
ss.beginTransaction();
User u=(User)ss.load(User.class,2);
System.out.println(u.getUsername().toString());
ss.getTransaction().commit();
} catch (Exception e) {
e.printStackTrace();
ss.getTransaction().rollback();
}finally{
if(ss!=null) ss.close();
}
}
@Test
public void cc(){
System.out.println("jalsdjflajsdfl;a");
Session ss=null;
try {
ss=HibernateUtils.openSession();
ss.beginTransaction();
User u=(User)ss.load(User.class,2);
u.setNickname("阿的说法的");
ss.save(u);
ss.getTransaction().commit();
} catch (Exception e) {
e.printStackTrace();
ss.getTransaction().rollback();
}finally{
if(ss!=null) ss.close();
}
}
@Test
public void dd(){
System.out.println("jalsdjflajsdfl;a");
Session ss=null;
try {
ss=HibernateUtils.openSession();
ss.beginTransaction();
User u=ss.get(User.class,2);
ss.delete(u);
ss.getTransaction().commit();
} catch (Exception e) {
e.printStackTrace();
ss.getTransaction().rollback();
}finally{
if(ss!=null) ss.close();
}
}
@Test
public void ee(){
System.out.println("jalsdjflajsdfl;a");
Session ss=null;
try {
ss=HibernateUtils.openSession();
//取出所有数据，from后面的User表示的是hiber映射的类，不是表名
//List<User> users=ss.createQuery("from User").list();
//分页
// List<User> users=ss.createQuery("from User").setFirstResult(0).setMaxResults(2).list();
// for(User u:users)
// {
// System.out.println(u.getId() + "," + u.getUsername());
// }
//执行sql查询，无法返回json格式数据
// List<Object[]> users1=ss.createSQLQuery("select * from t_user").list();
// for(Iterator<Object[]> it=users1.iterator();it.hasNext();)
// {
// Object[] s=it.next();
// System.out.println(s[0].toString()+","+s[1].toString());
// }
//执行sql查询，用字段名获取记录集中某字段的值
List users=ss.createSQLQuery("select * from t_user").setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP).list();
for(Iterator<Map> it=users.iterator();it.hasNext();)
{
Map s=it.next();
System.out.println(s.get("id")+","+s.get("username")+","+s.get("nickname")+ "," +s.get("email"));
}
//
for(int i=0;i<users.size();i++)
{
Map s=(Map)users.get(i);
System.out.println(s.get("id")+","+s.get("username")+","+s.get("nickname")+ "," +s.get("email"));
}
//
Iterator it=users.iterator();
while(it.hasNext())
{
Map s=(Map)it.next();
System.out.println(s.get("id")+","+s.get("username")+","+s.get("nickname")+ "," +s.get("email"));
}
} catch (Exception e) {
e.printStackTrace();
}finally{
if(ss!=null) ss.close();
}
}
}
使用hibernate sql 查询，利用map获取字段值，结果如下。
Hibernate: select * from t_user
1,ljlj,???,[email protected]
3,ljlj,你好,[email protected]
4,ljlj,???,[email protected]
5,ljlj,???,[email protected]
6,ljlj,捡垃圾,[email protected]
7,ljlj,捡垃圾,[email protected]
8,ljlj,捡垃圾,[email protected]
9,ljlj,捡垃圾,[email protected]
10,ljlj,捡垃圾,[email protected]
11,ljlj,捡垃圾,[email protected]
12,ljlj,捡垃圾,[email protected]
13,ljlj,捡垃圾,[email protected]
附：
Hibernate的session.createSQLQuery的几种查询方式
当我们用HQL进行子查询的时候，如select * from Tree where pid in (select id from Tree，此时HIBERANTE就会报错，说什么*号错误之类的。但如果将*改为Tree类里的所有子段时就不会有问题了。就会像平时一样第一行数据返 回一个Object[]，然后你再根据Tree类里字段对Object[]数组里的值进行转换。这样一来比较麻烦。今天发现如果我SQL来查有一个方法可 以返回一个对象的。
Configuration config = new Configuration().configure();
SessionFactory sf = config.buildSessionFactory();
Session session = sf.openSession();
Transaction ts = session.beginTransaction();
Query query = session.createSQLQuery("select * from Tree t where pid in (select id from Tree) ").addEntity(Tree.class); //返回对象
List list = query.list();
此时在遍历list时就可以(Tree)list.get[i];将每一行的内容变换为一个对象了。
另还可以返回一个Map对象，也就是说在在list里包含多个Map，代码如下
Query query = session.createSQLQuery("select id,name from Tree t where pid in (select id from Tree) ").setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP); //返回一个map,KEY:为DB中名称一致（大小写一致）遍历list时就可以
Map map = (Map)list.get[i];
map.get("id");map.get("name");来取值。按你的SQL语句select后的字段名来作为map的Key，但这个key必须与数据库中的字段名一模一样。
还可以用作函数方面的。如
Query query = session.createSQLQuery("select sum(id) SUMID from Tree t where pid in (select id from Tree)
.addScalar("SUMID",Hibernate.INTEGER) //转换类型，按DB中的type转
.setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP); //返回一个map,KEY:为DB中名称一致（大小写一致）
直接就map.get("SUMID")可以取值了
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