Hibernate ORM框架——Hibernate查询之Criteria接口、Native SQL 查询、Query接口（批量操作）

一、使用双向一对多，多对一的案例

util包不变、映射文件、配置文件不变

添加了一个实体（用于setResultTransformer）：

package shuang.m2oo2m;

public class PersonClassInfo {
    private String pname;
    private String cname;
    
    public String getPname() {
        return pname;
    }
    public void setPname(String pname) {
        this.pname = pname;
    }
    public String getCname() {
        return cname;
    }
    public void setCname(String cname) {
        this.cname = cname;
    }
    @Override
    public String toString() {
        return "PersonClassInfo [pname=" + pname + ", cname=" + cname + "]";
    }
    
    
}

Main测试

package com.nf;

import java.util.List;
import java.util.Map;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Restrictions;
import org.hibernate.query.NativeQuery;
import org.hibernate.query.Query;
import org.hibernate.transform.Transformers;

import shuang.m2oo2m.Person;
import shuang.m2oo2m.PersonClassInfo;
import util.HibernateUtil;

public class Main {

    public static void main(String[] args) {
        
        /*Criteria接口，单个模糊查询，组合类型模糊查询*/
        queryByCriteria();
        
        /*本地查询：即使用select语句查询*/
        //nativeQuery() ;
        
        /*本地查询：自己写的select查询语句：多表查询*/
        //nativeQueryTransformer();
        
        //批量添加、删除
        batchProcess();
    }

    private static void template() {
        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session s = sf.openSession();
        Transaction tx = s.beginTransaction();

        tx.commit();
        s.close();
        sf.close();
    }


    // ********************过滤条件*************************
    // 过滤条件值是固定的
    private static void fixedWhereQuery() {
        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session s = sf.openSession();
        Transaction tx = s.beginTransaction();

        String hql = "select p from Person p where p.name='p111'";

        Query q = s.createQuery(hql);
        List<Person> list = q.list();
        for (Person p : list) {
            System.out.println(p);
        }
        tx.commit();
        s.close();
        sf.close();
    }


    //Criteria接口主要是针对查询条件进行的操作
    //第一个Criteria接口案例-->like
    private static void queryByCriteria() {
        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session s = sf.openSession();
        Transaction tx = s.beginTransaction();

        Criteria c = s.createCriteria(Person.class);
        // 构造函数是受保护的，所以不能直接实例化
        //    Criterion guolv = new LikeExpression("name","abc");
        /*
         * 拓展：构造函数受保护的解决方案：
         * （1）直接：在自己的类中写一个父类静态的方法、方便调用
         * （2）间接：借用别人写好的工具类，里面写好的调用方法
         * */
        
        /*模糊查询：*/
        Criterion guolv = Restrictions.like("name","p%");
        c.add(guolv);
        
        /*组合类型：Restrictions.and*/
        /*
        Criterion startWithP = Restrictions.like("name", "p%");
        Criterion endWith5 = Restrictions.like("name", "%5");
        Criterion guolv = Restrictions.and(startWithP,endWith5);
        
        c.add(guolv);
        */
        
        List<Person> result = c.list();
        for(Person p: result) {
            System.out.println(p);
        }
        tx.commit();
        s.close();
        sf.close();
    }
    
    /*本地查询：即使用select语句查询*/
    private static void nativeQuery() {
        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session s = sf.openSession();
        Transaction tx = s.beginTransaction();
        
        NativeQuery q =  s.createNativeQuery("select * from persons", Person.class);
    
        List<Person> result = q.list();
        for(Person p: result) {
            System.out.println(p);
        }
        tx.commit();
        s.close();
        sf.close();
    }
    
    /*本地查询：自己写的select查询语句：多表查询*/
    private static void nativeQueryTransformer() {
        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session s = sf.openSession();
        Transaction tx = s.beginTransaction();
        
        NativeQuery q =  s
                .createNativeQuery("select persons.name as pname,CLASSINFO.name as cname from persons inner join classInfo on persons.rci = CLASSINFO.cid");
        q.setResultTransformer(Transformers.aliasToBean(PersonClassInfo.class));//为的是知道是哪个类
        
        List<PersonClassInfo> result = q.list();
        for(PersonClassInfo p: result) {
            System.out.println(p);
        }
        
        tx.commit();
        s.close();
        sf.close();
    }
    
    
    /*批量添加删除
     * batch批量的意思
     * Hibernate 对update，delete操作支持比较好
     * 而且hql的update，delete主要用来批量处理的
     * 但是对insert操作，支持就有限制
     * 不支持insert into xxx(id,name) values(1,'sss')
     * 但其支持的是insert into xxx(id,name) select
     */
    private static void batchProcess() {
        SessionFactory sf = HibernateUtil.getSessionFactory();
        Session s = sf.openSession();
        Transaction tx = s.beginTransaction();
        
        String hql = "update Person p set p.name = p.name + 'abc'  ";
        Query q = s.createQuery(hql);
        q.executeUpdate();
        
        tx.commit();
        s.close();
        sf.close();
    }
}