1 package com.rong.entity.hql; 2 ?3 public class User { 4 ?????5 ????public User(int id, String name) { 6 ????????super(); 7 ????????this.id = id; 8 ????????this.name = name; 9 ????}10 ????public User() {11 ????????super();12 ????}13 ????private int id;14 ????private String name;15 ????public int getId() {16 ????????return id;17 ????}18 ????public void setId(int id) {19 ????????this.id = id;20 ????}21 ????public String getName() {22 ????????return name;23 ????}24 ????public void setName(String name) {25 ????????this.name = name;26 ????}27 }

 1 package com.rong.entity.hql; 2 ?3 import javax.persistence.Entity; 4 import javax.persistence.GeneratedValue; 5 import javax.persistence.GenerationType; 6 import javax.persistence.Id; 7 ?8 @Entity 9 public class Student {10 ????@Id11 ????@GeneratedValue(strategy=GenerationType.AUTO)12 ????private int id;13 ????private String name;14 ????private int age;15 ????public int getId() {16 ????????return id;17 ????}18 ????public void setId(int id) {19 ????????this.id = id;20 ????}21 ????public String getName() {22 ????????return name;23 ????}24 ????public void setName(String name) {25 ????????this.name = name;26 ????}27 ????public int getAge() {28 ????????return age;29 ????}30 ????public void setAge(int age) {31 ????????this.age = age;32 ????}33 }

 ?1 package com.rong.entity.hql; ?2 ??3 import java.util.Iterator; ?4 import java.util.List; ?5 import java.util.Map; ?6 import java.util.Map.Entry; ?7 import java.util.Set; ?8 ??9 import org.hibernate.Query; 10 import org.hibernate.Session; 11 import org.hibernate.SessionFactory; 12 import org.hibernate.Transaction; 13 import org.hibernate.boot.registry.StandardServiceRegistryBuilder; 14 import org.hibernate.cfg.Configuration; 15 import org.hibernate.service.ServiceRegistry; 16 import org.junit.After; 17 import org.junit.Before; 18 import org.junit.Test; 19 //hql语句(面向)：类 ??对象 ??属性 20 public class TestHQL { 21 ????SessionFactory sessionFactory; 22 ????Session session; 23 ????Transaction transaction; 24 ????@Before 25 ????public void init() { 26 ????????Configuration configuration = new Configuration().configure(); 27 ????????ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder() 28 ????????????????????????.applySettings(configuration.getProperties()).build(); 29 ????????sessionFactory=configuration.buildSessionFactory(serviceRegistry); 30 ????????session = sessionFactory.openSession(); 31 ????????transaction = session.beginTransaction(); 32 ?????????33 ????} 34 ????//插入数据 35 ????@Test 36 ????public void addData(){ 37 ????????Student student=null; 38 ????????for(int i=1;i<=100;i++){ 39 ????????????student=new Student(); 40 ????????????student.setAge(i); 41 ????????????student.setName("先生"+i); 42 ????????????session.save(student); 43 ????????} 44 ????} 45 ????//查询所有的学生 (所有列) 46 ????@Test 47 ????public void test1(){ 48 ????????Query query = session.createQuery("from Student");//Student是类名 49 ????????List<Student> list = query.list(); 50 ????????System.out.println(list.size()); 51 ????????for (Student student : list) { 52 ????????????System.out.println(student.getAge()+student.getName()); 53 ????????} 54 ????} 55 ????//查询所有的学生当中的某一列 56 ????@Test 57 ????public void test2(){ 58 ????????//Student是类名，name是Student类的成员变量名 59 ????????Query query = session.createQuery("select s.name from Student s"); 60 ????????List<Student> list = query.list(); 61 ????????System.out.println(list); 62 ????} 63 ????//查询所有学生中的多列 64 ????@Test 65 ????public void test3(){ 66 ????????Query query = session.createQuery("select s.name,s.age from Student s"); 67 ????????//Query query = session.createQuery("select name,age from Student s"); 68 ????????List<Object[]> list = query.list(); 69 ????????//list集合的每一个元素都是数组，而每一个数组都是由name和age构成 70 ????????for (Object[] objects : list) { 71 ????????????for (Object object : objects) { 72 ????????????????System.out.print(object); 73 ????????????} 74 ????????????System.out.println(); 75 ????????} 76 ????} 77 ????//分页查询 78 ????@Test 79 ????public void test4(){ 80 ????????//Query query = session.createQuery("select s from Student s"); 81 ????????Query query = session.createQuery("from Student"); 82 ????????query.setFirstResult(0);//设置从哪里开始 83 ????????query.setMaxResults(3);//分页的条目 84 ????????List<Student> list = query.list(); 85 ????????for (Student student : list) { 86 ????????????System.out.println(student.getAge()+student.getName()); 87 ????????} 88 ????} 89 ????//查询所有的学生的某些字段 返回值是map类型,即获取List<Map<String,Object>>结果 90 ????@Test 91 ????public void test5(){ 92 ????????//这个是没有别名的 93 ????????//Query query = session.createQuery("select new map(s.name,s.age) from Student s"); 94 ????????//这个有别名的(修改key的值 就需要增加别名) 95 ????????Query query = session.createQuery("select new map(s.name as name,s.age as age) from Student s"); 96 ????????List<Map<String,Object>> list = query.list(); 97 ????????//结果 key是 从0 开始的 98 ????????//System.out.println(list);//[{0=先生1, 1=1}, {0=先生2, 1=2}, {0=先生3, 1=3}......] 99 ????????System.out.println(list);//[{name=先生1, age=1}, {name=先生2, age=2}......]100 ????????for (Map<String, Object> map : list) {101 ????????????Set<Entry<String, Object>> set = map.entrySet();102 ????????????Iterator<Entry<String, Object>> iterator = set.iterator();103 ????????????while(iterator.hasNext()){104 ????????????????Entry<String, Object> entry = iterator.next();105 ????????????????System.out.println(entry.getKey()+entry.getValue());106 ????????????}107 ????????}108 ????}109 ????//查询所有的学生的某些字段，返回值是list类型,即获取List<List<Object>>结果110 ????@Test111 ????public void test6(){112 ????????Query query = session.createQuery("select new list(s.name,s.age) from Student s");113 ????????List<List<Object>> list = query.list();114 ????????for (List<Object> li : list) {115 ????????????for (Object object : li) {116 ????????????????System.out.print(object);117 ????????????}118 ????????????System.out.println();119 ????????}120 ????}121 ????//查询student表，返回值是User,User类必须要有public User(int id, String name)的构造方法！！！122 ????@Test123 ????public void test7(){124 ????????Query query = session.createQuery("select new com.rong.entity.hql.User(s.id,s.name) from Student s");125 ????????List<User> list = query.list();126 ????????for (User user : list) {127 ????????????System.out.println(user.getId()+user.getName());128 ????????}129 ????}130 ????131 ????132 ????@After133 ????public void destroy(){134 ????????transaction.commit();135 ????????session.close();136 ????????sessionFactory.close();137 ????}138 }