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Hibernate笔记：HQL查询总结（二）——条件查询（转）

2014-01-24 11:44 507 查看

条件查询

1.拼字符串

where条件后面，可以用字符串连接组成条件

String hql = " select s.id, s.name from Student s where s.name like
'%1%'";
Query query = session.createQuery(hql);
List list = query.list();
for (Iterator
iter=students.iterator(); iter.hasNext();) {

Object[] obj = (Object[])iter.next();

System.out.println(obj[0] + "," + obj[1]);

}

2.可以采用？来传递参数（索引从0开始）

（1）分开设值

//条件查询，参数索引值从0开始，索引位置。通过setString,setParameter设置参数String hql = "from Users where name=? and passwd=?";
Query query = session.createQuery(hql);

//第1种方式
//query.setString(0, "name1");
//query.setString(1, "password1");

//第2种方式
query.setParameter(0, "name1",Hibernate.STRING);
query.setParameter(1, "password1",Hibernate.STRING);
List<Users> list = query.list();

for(Users users : list){
System.out.println(users.getId());
}

（2）方法链

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]);

}

3.使用：参数名称的方式传递参数值

//条件查询，自定义索引名(参数名):username,:password.通过
//setString,setParameter设置参数
String hql = "from Users where name=:username and passwd=:password";
Query query = session.createQuery(hql);

//第1种方式
//query.setString("username", "name1");
//query.setString("password", "password1");

//第2种方式,第3个参数确定类型
query.setParameter("username", "name1",Hibernate.STRING);
query.setParameter("password", "password1",Hibernate.STRING);

//第3种方式
//query = query.setParameter("username", "name1").setParameter
//("password", "password1");

List<Users> list = query.list();

for(Users users : list){
System.out.println(users.getId());
}

4.支持谓词in，需要使用setParameterList进行参数传递

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]);

}

5.在HQL中使用数据库的函数

List students = session.createQuery("select s.id, s.name from Student s
         where date_format(s.createTime, '%Y-%m')=?")

         .setParameter(0, "2010-12")

         .list();

for (Iterator iter=students.iterator(); iter.hasNext();) {

    Object[] obj = (Object[])iter.next();

    System.out.println(obj[0] + "," + obj[1]);

}

6.查询时间段的数据

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("2010-12-01 00:00:00"))

         .setParameter(1, sdf.parse("2010-12-31 23:59:59"))

               .list();

for (Iterator iter=students.iterator(); iter.hasNext();) {

    Object[] obj = (Object[])iter.next();

    System.out.println(obj[0] + "," + obj[1]);

}

转自http://www.cnblogs.com/a1280055207/archive/2013/01/10/2854261.html

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