package com.mengya.dao;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.SQLQuery;
import org.hibernate.Transaction;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Expression;
import org.hibernate.criterion.Order;

import com.mengya.entity.Stu;
import com.mengya.util.SessionFactoryUitl;

/**
?* Query query=this.GetSession().createQuery(hql); query.iterate()与query.list()
?* 效率是说query.iterate()比query.list()好，但做了N+1次查询 它们都是先从数据库的查询出主键值，然后根据主键值查询出对象，
?* 只是query.iterate()会根据主键值先从缓存当中找,若没有就从数据库查询 query.list()会根据主键值在数据库查询(N+1)
?*/

public class StuDAO extends SessionFactoryUitl {
?private Transaction tran;

?/**
? * 添加
? */
?public void save(Stu stu) {
??try {
???tran = this.GetSession().beginTransaction();
???this.GetSession().save(stu);
???tran.commit();
??} catch (HibernateException e) {
???throw e;
??} finally {
???this.CloseSession();
??}
?}

?/**
? * 使用HQL全查询
? */
?public List getallbyHQL() {
??List arr = null;
??try {
???String hql = "from Stu";
???Query query = this.GetSession().createQuery(hql);
???arr = query.list();
??} catch (HibernateException e) {
???throw e;
??} finally {
???this.CloseSession();
??}
??return arr;
?}

?/**
? * 使用Criteria全查询
? */
?public List getallbyCriteria() {
??List arr = null;
??try {
???Criteria cri = this.GetSession().createCriteria(Stu.class);
???arr = cri.list();
??} catch (HibernateException e) {
???throw e;
??} finally {
???this.CloseSession();
??}
??return arr;
?}

?/**
? * 根据主键查询
? */
?public Stu getbyID(int id) {
??Stu stu = null;
??try {
???stu = (Stu) this.GetSession().get(Stu.class, id);
??} catch (HibernateException e) {
???throw e;
??} finally {
???this.CloseSession();
??}
??return stu;
?}

?/**
? * 根据对象属性查询（使用Query）
? */
?public List getbyPropertyQuery(String name) {
??List arr = null;
??try {
???// 这里不能像SQL语一样select * from Stu where SName=:name,这是不对的。
???// Query query=this.GetSession().createQuery("from Stu where
???// SName=:name");
???// query.setString("name", name);
???// 或者
???Query query = this.GetSession().createQuery(
?????"from Stu where SName=?");
???query.setString(0, name);
???arr = query.list();
??} catch (HibernateException e) {
???throw e;
??} finally {
???this.CloseSession();
??}
??return arr;
?}

?/**
? * 根据对象属性查询(使用Criteria)
? */
?public List getbyPropertyCriteria(String name) {
??List arr = null;
??try {
???Criteria cri = this.GetSession().createCriteria(Stu.class);
???Criterion c1 = Expression.eq("SName", name);
???cri.add(c1);
???arr = cri.list();
??} catch (HibernateException e) {
???throw e;
??} finally {
???this.CloseSession();
??}
??return arr;
?}

?/**
? * 查询部分属性
? */
?public List getProperty() {
??List arr = new ArrayList();
??try {
???String hql = "select s.SName,s.SSex from Stu as s";
???Query query = this.GetSession().createQuery(hql);
???List list = query.list();
???Iterator iter = list.iterator();
???while (iter.hasNext()) {
????Object[] obj = (Object[]) iter.next();
????Stu s = new Stu();
????s.setSName(obj[0].toString());
????s.setSSex(obj[1].toString());
????arr.add(s);
???}
??} catch (HibernateException e) {
???this.CloseSession();
??}
??return arr;
?}

?/**
? * 查询一个属性
? */
?public List getoneProperty() {
??List arr = new ArrayList();
??try {
???String hql = "select s.SName from Stu as s";
???Query query = this.GetSession().createQuery(hql);
???Iterator iter = qu