Hibernate支持三种查询语言：HQL查询、Criteria查询和原生SQL查询
HQL(hibernate Query Language，hibernate查询语言)是一种面向对象查询语言，其中没有表和字段的概念，只有类、对象和属性的概念
语法：
form子句：form +全类名 / form + 类名（查询所有）
select子句：select dept.deptname from Dept
where子句：from dept where deptName=‘sales‘;
HQL执行语句
例子：form子句、select子句、where子句以及参数查询
建立实体类
public class Dept { ???private Integer deptno; ???private String dname; ???public Dept() { ???} ???public Dept(Integer deptno, String dname) { ???????this.deptno = deptno; ???????this.dname = dname; ???} ???public Integer getDeptno() { ???????return deptno; ???} ???public void setDeptno(Integer deptno) { ???????this.deptno = deptno; ???} ???public String getDname() { ???????return dname; ???} ???public void setDname(String dname) { ???????this.dname = dname; ???}}测试方法
package cn;import cn.happy.entity.Dog;import cn.hib.entity.Dept;import org.hibernate.Query;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.junit.Before;import org.junit.Test;import java.util.List;/** * Created by a on 2017/8/20. */public class Test924 { ???Configuration cfg; ???SessionFactory factory; ???Session session; ???Transaction tx; ???@Before ???public void beforeTest(){ ???????//创建配置对象 ???????cfg=new Configuration().configure(); ???????//根据配置对象创建SessonFactory ???????factory=cfg.buildSessionFactory(); ???????//根据SessionFactory创建Session ???????session=factory.getCurrentSession(); ???????//session=factory.openSession(); ???????//开启事务 ???????tx=session.beginTransaction(); ???} ???@Test ???public void testlist(){ ???????String hql="from Dept"; ???????Query query=session.createQuery(hql); ???????List<Dept> list=query.list(); ???????for (Dept dept : list){ ???????????System.out.println(dept.getDname()); ???????} ???} ???@Test ???public void selectSomeColumnFromTable(){ ???????String hql="select dept.deptno,dept.dname from Dept"; ???????Query query=session.createQuery(hql); ???????List<Object[]>list=query.list(); ???????for(Object[] obj : list){ ???????????for (Object child : obj){ ???????????????System.out.println(child); ???????????} ???????} ???} ???@Test ???public void selectSomesColumnFromTable(){ ???????String hql="select new Dept(dept.deptno,dept.dname) from Dept dept"; ???????Query query=session.createQuery(hql); ???????List<Dept> list=query.list(); ???????for (Dept dept : list){ ???????????System.out.println(dept.getDname()); ???????} ???} ???@Test ???public void selectSomeRecordsFromTable(){ ???????String hql="from dept.deptno,dept.dname from Dept dept where dept.dname=‘RESEARCH‘"; ???????Query query=session.createQuery(hql); ???????List<Dept> list=query.list(); ???????for (Dept dept : list){ ???????????System.out.println(dept.getDname()); ???????} ???} ???//案例：参数查询： 方案一：匿名占位符“?” ???@Test ???public void selectByConditionNiming(){ ???????String hql="from Dept dept where dname=?"; ???????Query query=session.createQuery(hql); ???????query.setParameter(0,"RESEARCH"); ???????List<Dept> list=query.list(); ???????for(Dept dept : list){ ???????????System.out.println(dept.getDname()); ???????} ???} ???//案例：参数查询：方案二： ???@Test ???public void selectByConditionParametername(){ ???????String hql="from Dept dept where dname=:dname"; ???????Query query=session.createQuery(hql); ???????query.setParameter("dname","RESEARCH"); ???????List<Dept> list=query.list(); ???????for(Dept dept : list){ ???????????System.out.println(dept.getDname()); ???????} ???} ???//案例：参数查询：方案三：name 参数名称绑定++++对象属性 ???@Test ???public void selectByConditionParameternameAndObjectAttribute(){ ???????String hql="from Dept dept where dname=:dname"; ???????Dept dd=new Dept(); ???????dd.setDname("RESEARCH"); ???????Query query=session.createQuery(hql); ???????query.setProperties(dd); ???????List<Dept> list=query.list(); ???????for(Dept dept : list){ ???????????System.out.println(dept.getDname()); ???????} ???}}Hibernate=====HQL实用技术
原文地址：http://www.cnblogs.com/hfddz/p/7591478.html