Hibernate的批量查询——Criteria

1、查询所有的学生信息：

public static void testSel() {
            Session session = HibernateUtils.openSession();
            Transaction transaction = session.beginTransaction();
            Criteria criteria=session.createCriteria(Student.class);
            List<Student>list= criteria.list();
            System.out.println(list);
            transaction.commit();
            session.close();
        }

 2、条件查询：

运算符与对应的英文缩写：

> gt　　>=ge　　<lt　　<=le　　==eq

!=ne　　in:in　　between and:：between

like:like　　is not null:isNotNull　　

or:or　　and:and

(1)eq的运用：

public static void testSel() {
            Session session = HibernateUtils.openSession();
            Transaction transaction = session.beginTransaction();
            Criteria criteria=session.createCriteria(Student.class);
            criteria.add(Restrictions.eq("sex","女"));
            List<Student>list= criteria.list();
            System.out.println(list);
            transaction.commit();
            sessio

 （2）like的运用：

public static void testSel() {
            Session session = HibernateUtils.openSession();
            Transaction transaction = session.beginTransaction();
            Criteria criteria=session.createCriteria(Student.class);
            criteria.add(Restrictions.like("sname","许__"));
            List<Student>list= criteria.list();
            System.out.println(list);
            transaction.commit();
            session.close();
        }

 3、分页查询：

需要事先设置起始位置和查询的数量。

public static void testSel() {
            Session session = HibernateUtils.openSession();
            Transaction transaction = session.beginTransaction();
            Criteria criteria=session.createCriteria(Student.class);
            criteria.add(Restrictions.eq("sex","女"));
            criteria.setFirstResult(1);
            criteria.setMaxResults(2);
            List<Student>list= criteria.list();
            System.out.println(list);
            transaction.commit();
            session.close();
        }

4、总记录数的获取：

public static void testSel() {
            Session session = HibernateUtils.openSession();
            Transaction transaction = session.beginTransaction();
            Criteria criteria=session.createCriteria(Student.class);
            criteria.setProjection(Projections.rowCount());//聚合函数获得总行数
            Long rowNum= (Long) criteria.uniqueResult();
            System.out.println(rowNum);
            List<Student>list= criteria.list();
            System.out.println(list);
            transaction.commit();
            session.close();
        }