Restrictions用法

1. Criteria 爲條件查詢

   Criterion 爲條件

   通過Criteria的add即可將Criterion條件添加

2. 方法說明

方法	說明
Restrictions.eq	＝
Restrictions.allEq	利用Map來進行多個等於的限制
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限定查詢

 

 

2，QBC常用限定方法

Restrictions.eq --> equal,等於.

Restrictions.allEq --> 參數爲Map對象,使用key/value進行多個等於的比對,相當於多個Restrictions.eq的效果

Restrictions.gt --> great-than > 大於

Restrictions.ge --> great-equal >= 大於等於

Restrictions.lt --> less-than, < 小於

Restrictions.le --> less-equal <= 小於等於

Restrictions.between --> 對應SQL的between子句

Restrictions.like --> 對應SQL的LIKE子句

Restrictions.in --> 對應SQL的in子句

Restrictions.and --> and 關係

Restrictions.or --> or 關係

Restrictions.isNull --> 判斷屬性是否爲空,爲空則返回true

Restrictions.isNotNull --> 與isNull相反

Restrictions.sqlRestriction --> SQL限定的查詢

Order.asc --> 根據傳入的字段進行升序排序

Order.desc --> 根據傳入的字段進行降序排序

MatchMode.EXACT --> 字符串精確匹配.相當於"like 'value'"

MatchMode.ANYWHERE --> 字符串在中間匹配.相當於"like '%value%'"

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

MatchMode.END --> 字符串在最後面的位置.相當於"like '%value'"

例子
查詢年齡在20-30歲之間的所有學生對象
List list = session.createCriteria(Student.class)
.add(Restrictions.between("age",new Integer(20),new Integer(30)).list();
查詢學生姓名在AAA,BBB,CCC之間的學生對象
String[] names = {"AAA","BBB","CCC"};
List list = session.createCriteria(Student.class)
.add(Restrictions.in("name",names)).list();
查詢年齡爲空的學生對象
List list = session.createCriteria(Student.class)
.add(Restrictions.isNull("age")).list();
查詢年齡等於20或者年齡爲空的學生對象
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實現動態查詢
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"));//根據名字升序排列
return criteria.list();
}

 

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今天用了寫hibernate高級查詢時用了Restrictions(當然Expression也是可以以的)這個類.感覺不錯.
下面的代碼寫的不易讀.其實核心就是一句
Restrictions.or(Restrictions.like(),Restrictions.or(Restrictions.like,........))
裏面的or可以無限加的.還是比較好用

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;