hibernate实例简析-hibernate_hql（二）

 

1、条件查询【重要】 
 * 可以采用拼字符串的方式传递参数
 * 可以采用 ？来传递参数（索引从0开始）
 * 可以采用 :参数名 来传递参数
 * 如果传递多个参数，可以采用setParamterList方法
 * 在hql中可以使用数据库的函数，如：date_format
 参见：SimpleConditionQueryTest.java

SimpleConditionQueryTest

List students = session.createQuery("select s.id, s.name from Student s where s.name like '%1%'").list();
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Object[] obj = (Object[])iter.next();
    System.out.println(obj[0] + "," + obj[1]);
   }

 

====

List students = session.createQuery("select s.id, s.name from Student s where s.name like ?")
               .setParameter(0, "%1%")
               .list();
   
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Object[] obj = (Object[])iter.next();
    System.out.println(obj[0] + "," + obj[1]);
   }

=====

List students = session.createQuery("select s.id, s.name from Student s where s.name like :myname")
               .setParameter("myname", "%1%")
               .list();
   
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Object[] obj = (Object[])iter.next();
    System.out.println(obj[0] + "," + obj[1]);
   }

====

List students = session.createQuery("select s.id, s.name from Student s where s.name like :myname and s.id=:myid")
               .setParameter("myname", "%1%")
               .setParameter("myid", 12)
               .list();
   
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Object[] obj = (Object[])iter.next();
    System.out.println(obj[0] + "," + obj[1]);
   }

====

List students = session.createQuery("select s.id, s.name from Student s where s.id in(:myids)")
         .setParameterList("myids", new Object[]{1, 2, 3, 4, 5})
               .list();
   
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Object[] obj = (Object[])iter.next();
    System.out.println(obj[0] + "," + obj[1]);
   }

===

List students = session.createQuery("select s.id, s.name from Student s where date_format(s.createTime, '%Y-%m')=?")
         .setParameter(0, "2008-02")
               .list();
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Object[] obj = (Object[])iter.next();
    System.out.println(obj[0] + "," + obj[1]);
   }

===

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   
   List students = session.createQuery("select s.id, s.name from Student s where s.createTime between ? and ?")
         .setParameter(0, sdf.parse("2008-01-10 00:00:00"))
         .setParameter(1, sdf.parse("2008-02-15 23:59:59"))
               .list();
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Object[] obj = (Object[])iter.next();
    System.out.println(obj[0] + "," + obj[1]);
   }

 

2、分页查询【重要】 
 * setFirstResult()，从0开始
 * setMaxResults,每页显示多少条数据
 参见：PageQueryTest.java

List students = session.createQuery("from Student")
         .setFirstResult(1)
         .setMaxResults(2)
         .list();
   for (Iterator iter=students.iterator(); iter.hasNext();) {
    Student student = (Student)iter.next();
    System.out.println(student.getName());
   }