QBC和QBE
Criteria是Criterion的复数，是"标准、准则、约束"的意思。
用法：
@Test
public void testQBC() {
Session session = sf.openSession();
session.beginTransaction();
//criterion 标准/准则/约束
Criteria c = session.createCriteria(Topic.class) //from Topic
.add(Restrictions.gt("id", 2)) //greater than = id > 2
.add(Restrictions.lt("id", 8)) //little than = id < 8
.add(Restrictions.like("title", "t_"))
.createCriteria("category")
.add(Restrictions.between("id", 3, 5)) //category.id >= 3 and category.id <=5
;
//DetachedCriterea
for(Object o : c.list()) {
Topic t = (Topic)o;
System.out.println(t.getId() + "-" + t.getTitle());
}
session.getTransaction().commit();
session.close();
}
测试结果：
Hibernate:
select
this_.id as id2_1_,
this_.category_id as category4_2_1_,
this_.createDate as createDate2_1_,
this_.title as title2_1_,
category1_.id as id0_0_,
category1_.name as name0_0_
from
Topic this_
inner join
Category category1_
on this_.category_id=category1_.id
where
this_.id>?
and this_.id<?
and this_.title like ?
and category1_.id between ? and ?
QBE:(Query By Example)
QBE是QBC的一部分
//is empty and is not empty
//query by criteria query by example
@Test
public void testQBE() {
Session session = sf.openSession();
session.beginTransaction();
Topic tExample = new Topic();
tExample.setTitle("T_");
Example e = Example.create(tExample)
.ignoreCase().enableLike();
Criteria c = session.createCriteria(Topic.class)
.add(Restrictions.gt("id", 2))
.add(Restrictions.lt("id", 8))
.add(e)
;
for(Object o : c.list()) {
Topic t = (Topic)o;
System.out.println(t.getId() + "-" + t.getTitle());
}
session.getTransaction().commit();
session.close();
}
转载请注明出处:http://blog.csdn.net/acmman/article/details/43937517
