总结：Hibernate Restrictions 用法

QBC常用限定方法

Restrictions .eq   --> equal,等于.

Restrictions .ne   --> not equal,不等于.

Restrictions .allEq   --> 参数为Map对象,使用key/value进行多个等于的比对,相当于多个Restrictions .eq 的效果

Restrictions .gt   --> great-than > 大于

Restrictions .ge   --> great-equal >= 大于等于

Restrictions .lt   --> less-than, < 小于

Restrictions .le   --> less-equal <= 小于等于

Restrictions .between   --> 对应SQL的between子句

Restrictions .like   --> 对应SQL的LIKE子句

Restrictions .in   --> 对应SQL的in子句

Restrictions .and   --> and 关系

Restrictions .or   --> or 关系

Restrictions .isNull   --> 判断属性是否为空,为空则返回true

Restrictions .isNotNull   --> 与isNull相反

Restrictions .sqlRestriction   --> SQL限定的查询

Order.asc   --> 根据传入的字段进行升序排序

Order.desc   --> 根据传入的字段进行降序排序

MatchMode.EXACT   --> 字符串精确匹配.相当于"like 'value'"

MatchMode.ANYWHERE   --> 字符串在中间匹配.相当于"like '%value%'"

MatchMode.START   --> 字符串在最前面的位置.相当于"like 'value%'"

MatchMode.END   --> 字符串在最后面的位置.相当于"like '%value'"

例子
查询年龄在20-30岁之间的所有学生对象
List list = session.createCriteria(Student.class)
       .add(Restrictions .between("age",new Integer(20),new Integer(30)).list();
查询学生姓名在AAA,BBB,CCC之间的学生对象
String[] names = {"AAA","BBB","CCC"};
List list = session.createCriteria(Student.class)
       .add(Restrictions .in("name",names)).list();
查询年龄为空的学生对象
List list = session.createCriteria(Student.class)
       .add(Restrictions .isNull("age")).list();
查询年龄等于20或者年龄为空的学生对象
List list = session.createCriteria(Student.class)
       .add(Restrictions .or(Restrictions .eq("age",new Integer(20)),
                  Restrictions .isNull("age")).list();

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使用QBC实现动态查询  
public List findStudents(String name,int age){

Criteria criteria = session.createCriteria(Student.class);
if(name != null){
   criteria.add(Restrictions .liek("name",name,MatchMode.ANYWHERE));
}
if(age != 0){
   criteria.add(Restrictions .eq("age",new Integer(age)));
}
criteria.addOrder(Order.asc("name"));//根据名字升序排列
return criteria.list();
}

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今天用了写hibernate 高级查询时用了Restrictions (当然Expression也是可以以的)这个类.感觉不错.
下面的代码写的不易读.其实核心就是一句
Restrictions .or(Restrictions .like(),Restrictions .or(Restrictions .like,........))
里面的or可以无限加的.还是比较好用

Session session = getHibernateTemplate().getSessionFactory().openSession();
        Criteria criteria = session.createCriteria(Film.class);
        List<Film> list = criteria.add(
             Restrictions .or(Restrictions .like("description", key,MatchMode.ANYWHERE),
             Restrictions .or(Restrictions .like("name", key,MatchMode.ANYWHERE),
             Restrictions .or(Restrictions .like("direct", key,MatchMode.ANYWHERE),
             Restrictions .or(Restrictions .like("mainplay",key,MatchMode.ANYWHERE),
             Restrictions .like("filearea", key,MatchMode.ANYWHERE)))))).list();

        session.close();
        return list;