Hibernate相关的查询 --Hibernate框架基础

 ?1 package com.test; ?2 ??3 import java.util.List; ?4 ??5 import org.hibernate.Session; ?6 import org.junit.Test; ?7 ??8 import com.beans.Student; ?9 import com.utils.HbnUtils; 10 ?11 public class QueryTest { 12 ?13 ????/** 14 ?????* 添加测试数据 15 ?????*/ 16 ????@Test 17 ????public void test_01() { 18 ????????Session session = HbnUtils.getSession(); 19 ????????try { 20 ????????????session.beginTransaction(); 21 ????????????Student student1 = new Student("貂蝉", 20, 92); 22 ????????????Student student2 = new Student("王昭君", 22, 93); 23 ????????????Student student3 = new Student("杨玉环", 23, 94); 24 ????????????Student student4 = new Student("李师师", 24, 95); 25 ????????????Student student5 = new Student("苏小小", 25, 96); 26 ????????????Student student6 = new Student("李师师", 28, 96); 27 ????????????Student student7 = new Student("张云云", 20, 91); 28 ????????????session.save(student1); 29 ????????????session.save(student2); 30 ????????????session.save(student3); 31 ????????????session.save(student4); 32 ????????????session.save(student5); 33 ????????????session.save(student6); 34 ????????????session.save(student7); 35 ????????????session.getTransaction().commit(); 36 ????????} catch (Exception e) { 37 ????????????// TODO: handle exception 38 ????????????session.getTransaction().rollback(); 39 ????????????e.printStackTrace(); 40 ????????} 41 ????} 42 ?43 ????/** 44 ?????* 使用SQL语句查询学生信息（作比较） 45 ?????*/ 46 ????@Test 47 ????public void testQuery_SQL() { 48 ????????Session session = HbnUtils.getSession(); 49 ????????try { 50 ????????????session.beginTransaction(); 51 ????????????String sql = "SELECT tid,tname,tage,tscore FROM t_student "; 52 ????????????List<Student> list = session.createSQLQuery(sql) 53 ????????????????????.addEntity(Student.class).list(); 54 ????????????for (Student student : list) { 55 ????????????????System.out.println(student); 56 ????????????} 57 ????????????session.getTransaction().commit(); 58 ????????} catch (Exception e) { 59 ????????????// TODO: handle exception 60 ????????????e.printStackTrace(); 61 ????????????session.getTransaction().rollback(); 62 ????????} 63 ????} 64 ?65 ????/** 66 ?????* 使用HQL查询学生信息 67 ?????*/ 68 ????@Test 69 ????public void testQuery_HQL01() { 70 ????????Session session = HbnUtils.getSession(); 71 ????????try { 72 ????????????session.beginTransaction(); 73 ????????????String hql = "FROM Student ORDER BY tscore DESC"; 74 ????????????List<Student> list = session.createQuery(hql).list(); 75 ????????????for (Student student : list) { 76 ????????????????System.out.println(student); 77 ????????????} 78 ????????????session.getTransaction().commit(); 79 ????????} catch (Exception e) { 80 ????????????// TODO: handle exception 81 ????????????e.printStackTrace(); 82 ????????????session.getTransaction().rollback(); 83 ????????} 84 ????} 85 ?86 ????/** 87 ?????* 查询指定字段的信息 88 ?????*/ 89 ????@Test 90 ????public void testQuery_HQL_02() { 91 ????????Session session = HbnUtils.getSession(); 92 ????????try { 93 ????????????session.beginTransaction(); 94 ????????????String hql = "FROM Student WHERE id=:id";// :后的id：属性名，Studetn：类名 95 ????????????Student student = (Student) session.createQuery(hql) 96 ????????????????????.setInteger("id", 3).uniqueResult(); 97 ????????????System.out.println(student); 98 ????????????session.getTransaction().commit(); 99 ????????} catch (Exception e) {100 ????????????// TODO: handle exception101 ????????????e.printStackTrace();102 ????????????session.getTransaction().rollback();103 ????????}104 ????}105 106 ????/**107 ?????* 简单聚合查询108 ?????*/109 ????@Test110 ????public void testQuery_HQL_03() {111 ????????Session session = HbnUtils.getSession();112 ????????try {113 ????????????session.beginTransaction();114 ????????????String hql = "SELECT COUNT(*) from Student";115 ????????????Long count = (Long) session.createQuery(hql).uniqueResult();116 ????????????System.out.println(count);// 打印有多少条数据117 ????????????session.getTransaction().commit();118 ????????} catch (Exception e) {119 ????????????// TODO: handle exception120 ????????????e.printStackTrace();121 ????????????session.getTransaction().rollback();122 ????????}123 ????}124 125 ????/**126 ?????* 投影查询127 ?????*/128 ????@Test129 ????public void testQuery_HQL04() {130 ????????Session session = HbnUtils.getSession();131 ????????try {132 ????????????session.beginTransaction();133 ????????????String hql = "SELECT new ?Student(name,age) From Student";// 将查询到的字段通过构造方法封装到对象，然后保存在list中134 ????????????List<Student> list = session.createQuery(hql).list();135 ????????????for (Student student : list) {136 ????????????????System.out.println(student);//只查询到name、age信息，其他则为默认137 ????????????}138 ????????????session.getTransaction().commit();139 ????????} catch (Exception e) {140 ????????????// TODO: handle exception141 ????????????e.printStackTrace();142 ????????????session.getTransaction().rollback();143 ????????}144 ????}145 146 ????/**147 ?????* 查每个年龄段的第一个人148 ?????*/149 ????@Test150 ????public void testQuery_HQL05() {151 ????????Session session = HbnUtils.getSession();152 ????????try {153 ????????????session.beginTransaction();154 ????????????String hql = "FROM Student GROUP BY age";155 ????????????List<Student> list = session.createQuery(hql).list();156 ????????????for (Student student : list) {157 ????????????????System.out.println(student);158 ????????????}159 ????????????session.getTransaction().commit();160 ????????} catch (Exception e) {161 ????????????// TODO: handle exception162 ????????????e.printStackTrace();163 ????????????session.getTransaction().rollback();164 ????????}165 ????}166 167 ????/**168 ?????* 查询有几个年龄段169 ?????*/170 ????@Test171 ????public void testQuery_HQL06() {172 ????????Session session = HbnUtils.getSession();173 ????????try {174 ????????????session.beginTransaction();175 ????????????String hql= "select age from Student group by age";176 ????????????List<Integer> list = session.createQuery(hql).list();177 ????????????System.out.println(list);178 ????????????session.getTransaction().commit();179 ????????} catch (Exception e) {180 ????????????// TODO: handle exception181 ????????????e.printStackTrace();182 ????????????session.getTransaction().rollback();183 ????????}184 ????}185 186 ????/**187 ?????* 查询年龄大于1人的年龄段188 ?????*/189 ????@Test190 ????public void testQuery_HQL07() {191 ????????Session session = HbnUtils.getSession();192 ????????try {193 ????????????session.beginTransaction();194 ????????????String hql= "select age from Student group by age having count(age) > 1";195 ????????????List<Integer> list = session.createQuery(hql).list();196 ????????????System.out.println(list);197 ????????????session.getTransaction().commit();198 ????????} catch (Exception e) {199 ????????????// TODO: handle exception200 ????????????e.printStackTrace();201 ????????????session.getTransaction().rollback();202 ????????}203 ????}204 }