/**  * @Title: testSelectList  * @Description: 以List形式返回选择的属性* @throws  */  @Testpublic void testSelectList() {String hql = "select new list(s.sname,s.ssex,s.sage) from Student s";Query query = session.createQuery(hql);List<List> lists = query.list();for (List list : lists) {System.out.println("name:" + list.get(0) + " sex:" + list.get(1) + " age:" + list.get(2));}}

以map的形式返回结果

/**  * @Title: testSelectMap  * @Description: 以map的形式返回结果* @throws  */  @Testpublic void testSelectMap() {String hql = "select new map(s.sname,s.ssex,s.sage) from Student s";Query query = session.createQuery(hql);List<Map> maps = query.list();// 返回结果的   key 就是查询的顺序 value 就是返回的结果for (Map map : maps) {System.out.println("name:" + map.get("0") + " sex:" + map.get("1") + " age:" + map.get("2"));}}

以自定义类型返回结果

/**  * @Title: testSelectCustomType  * @Description: 以自定义类型返回结果* @throws  */  @Testpublic void testSelectCustomType() {// 自定义类中必须有相应的构造方法String hql = "select new Student(s.sname,s.ssex,s.sclass) from Student s";Query query = session.createQuery(hql);List<Student> students = query.list();for (Student student : students) {System.out.println("name:" + student.getSname() + " sex:" + student.getSsex() + " class:" + student.getSclass());}}

distinct关键字去除重复元素

 /**  * @Title: testSelectDistinct  * @Description: 使用distinct关键字去除重复元素* @throws  */  @Testpublic void testSelectDistinct() {String hql = "select distinct s.sclass from Student s";Query query = session.createQuery(hql);List<Object> objects = query.list();for (Object object : objects) {System.out.println(object);}}

3) WHERE子句

/**  * @Title: testWhere  * @Description: where子句* @throws  */  @Testpublic void testWhere() {/** 比较运算* 运算符  =  <>  <  >  >=  <=* null 值判断    is null/is not null*///        String hql = "from Student s where s.sage > 20";
//        String hql = "from Student s where s.sclass <> null";/** 范围运算* in / not in (候选值列表)* between / not between  值1 and 值2*///        String hql = "from Student s where s.sage in (20,25)";
//        String hql = "from Student s where s.sage not between 20 and 25";/** 字符串模式匹配* like关键字* 通配符  %：匹配任意个字符  _：匹配一个字符*///        String hql = "from Student s where s.sname like '_二'";
//        String hql = "from Student s where s.sname like '_二%'";/** 逻辑运算* and   or    not*///        String hql = "from Student s where s.sname like '_二' or s.sage = 20";/** 集合运算* is empty / is not empty  集合为空/不为空      empty ——> exists* member of  元素属于集合     member of ——>  in*///        String hql = "from Student s where s.scs is empty";/** 四则运算*   +  -  *  /*/String hql = "from Student s where s.sage + 2 > 21";Query query = session.createQuery(hql);List<Student> students = query.list();for (Student student : students) {System.out.println(student);}}

4）ORDER BY 对查询结果进行排序

/**  * @Title: testOrderBy  * @Description: order by 子句对查询结果进行排序* @throws  */  @Testpublic void testOrderBy() {
//        String hql = "from Student s order by s.sage";String hql = "from Student s order by s.sage asc , s.sid desc";Query query = session.createQuery(hql);List<Student> students = query.list();for (Student student : students) {System.out.println(student);}}

5） uniqueResult方法查询单个对象

 /**  * @Title: testUniqueResult  * @Description: uniqueResult方法查询单个对象，如果有多个结果会报错* @throws  */  @Testpublic void testUniqueResult() {String hql = "from Student s where s.sid = 1";Query query = session.createQuery(hql);Student student = (Student) query.uniqueResult();System.out.println(student);}