QBC常用限定方法，使用QBC实现动态查询 ，Restrictions

方法说明

方法	说明
Restrictions.eq	＝
Restrictions.allEq	利用Map来进行多个等于的限制
Restrictions.gt	＞
Restrictions.ge	＞＝
Restrictions.lt	＜
Restrictions.le	＜＝
Restrictions.between	BETWEEN
Restrictions.like	LIKE
Restrictions.in	in
Restrictions.and	and
Restrictions.or	or
Restrictions.sqlRestriction	用SQL限定查询

2，QBC常用限定方法

Restrictions.eq --> equal,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;