hibernate框架学习之数据查询（HQL）helloworld

package cn.itcast.h3.hql;import java.util.List;import org.hibernate.Query;import org.hibernate.Session;import cn.itcast.h3.hql.vo.StudentModel;import cn.itcast.h3.hql.vo.TeacherModel;import cn.itcast.h3.util.HibernateUtil;public class HQLApp { ???//测试简单查询 ???void testSimple(){ ???????Session s = HibernateUtil.getSession(); ???????????????//1.HQL ???????String hql = "from TeacherModel"; ???????//2.Query ???????Query q = s.createQuery(hql); ???????//3.获取查询结果 ???????List<TeacherModel> queryList = q.list(); ???????for(TeacherModel tm:queryList){ ???????????System.out.println(tm); ???????} ???????????????s.close(); ???} ???//链式格式 ???void testLinked(){ ???????Session s = HibernateUtil.getSession(); ???????????????//3.获取查询结果 ???????List<TeacherModel> queryList = s.createQuery( "from TeacherModel where uuid <=:uuid").setFirstResult(1).setMaxResults(3).setLong("uuid", 3L).list(); ???????????????for(TeacherModel tm:queryList){ ???????????System.out.println(tm); ???????} ???????????????s.close(); ???} ???//别名格式 ???void testAlias(){ ???????Session s = HibernateUtil.getSession(); ???????????????//1.HQL ???????String hql = "select um.nick from TeacherModel um"; ???????//2.Query ???????Query q = s.createQuery(hql); ???????//3.获取查询结果 ???????List<String> queryList = q.list(); ???????for(String tm:queryList){ ???????????System.out.println(tm); ???????} ???????????????s.close(); ???} ???//聚合函数 ???void testFunctoin(){ ???????Session s = HibernateUtil.getSession(); ???????//1.HQL ???????String hql = "select sum(age) from StudentModel"; ???????//2.Query ???????Query q = s.createQuery(hql); ???????Long avgAge = (Long) q.uniqueResult(); ???????System.out.println(avgAge); ???????s.close(); ???} ???//按条件查询 ???void testEntityQuery(){ ???????Session s = HibernateUtil.getSession(); ???????//1.HQL ???????//编号为4的老师有哪些学生// ???????String hql = "from StudentModel where ?teacher.uuid= :uuid";// ???????//2.Query// ???????Query q = s.createQuery(hql);// ???????q.setLong("uuid",4L); ???????????????String hql = "from StudentModel where teacher = :teacher"; ???????Query q = s.createQuery(hql); ???????TeacherModel tm = new TeacherModel(); ???????tm.setUuid(4L);// ???????tm.setTeacherName("李若亮"); ???????//为hql赋值对象参数 ???????q.setEntity("teacher", tm); ???????List<StudentModel> queryList = q.list(); ???????for(StudentModel sm:queryList){ ???????????System.out.println(sm); ???????} ???} ???//无条件查询 ???void testNoCondQuery(){ ???????Session s = HibernateUtil.getSession(); ???????????????String hql = "from TeacherModel where teacherName = nick"; ???????Query q = s.createQuery(hql); ???????List<TeacherModel> queryList = q.list(); ???????for(TeacherModel sm:queryList){ ???????????System.out.println(sm); ???????} ???} ???//投影查询 ???void testOtherQuery(){ ???????Session s = HibernateUtil.getSession(); ???????????????String hql = "select new TeacherModel(teacherName,nick) from TeacherModel"; ???????Query q = s.createQuery(hql); ???????List<TeacherModel> queryList = q.list(); ???????for(TeacherModel sm:queryList){ ???????????System.out.println(sm); ???????} ???} ???//投影查询list ???void testOtherQuery2(){ ???????Session s = HibernateUtil.getSession(); ???????????????String hql = "select new list(teacherName,nick) from TeacherModel"; ???????Query q = s.createQuery(hql); ???????List<List<String>> queryList = q.list(); ???????for(List<String> sm:queryList){ ???????????for(String sa:sm){ ???????????????System.out.println(sa); ???????????} ???????} ???} ???//查询分组 ???void testGroupQuery(){ ???????Session s = HibernateUtil.getSession(); ???????????????String hql = "select skill,count(skill) from StudentModel group by skill"; ???????Query q = s.createQuery(hql); ???????List<Object[]> queryList = q.list(); ???????for(Object[] objs:queryList){ ???????????for(Object obj:objs){ ???????????????System.out.print(obj+"\t"); ???????????} ???????????System.out.println(); ???????} ???} ???//查询分组 ???void testObejcts(){ ???????Session s = HibernateUtil.getSession(); ???????????????String hql = "from java.lang.Object"; ???????Query q = s.createQuery(hql); ???????List<Object> queryList = q.list(); ???????for(Object obj:queryList){ ???????????System.out.println(obj); ???????} ???} ???//配置格式的查询 ???void testConfQuery(){ ???????Session s = HibernateUtil.getSession(); ???????????????Query q = s.getNamedQuery("getAll"); ???????q.setString("name", "李若亮"); ???????List<Object> queryList = q.list(); ???????for(Object obj:queryList){ ???????????System.out.println(obj); ???????} ???} ???????public static void main(String[] args) { ???????new HQLApp().testConfQuery(); ???}}