String hql="select new map(t.title as title,t.id as id,t.link as link,t.linktitle as linktitle) from Article as t where t.category="+categoryid+" order by t.uploadtime desc";
Query query= getSessionFactory().getCurrentSession().createQuery(hql);
query.setFirstResult((pageNo - 1) * pageSize);
query.setMaxResults(pageSize);
List<Map> list = query.list();
for(Map article : list)
{
String title = (String)article.get("title");
System.out.println("文章標(biāo)題是"+title);
}
下面再介紹下相關(guān)的知識：
1 查詢其中幾個字段
String hql = " select name,passwd from Users";
Query query = session.createQuery(hql);
//默認(rèn)查詢出來的list里存放的是一個Object數(shù)組
List<Object[]> list = query.list();
for(Object[] object : list){
String name = (String)object[0];
String passwd = (String)object[1];
System.out.println(name + " : " + passwd);
}
2 修改默認(rèn)查詢結(jié)果(query.list())不以O(shè)bject[]數(shù)組形式返回，以List形式返回
//查詢其中幾個字段,添加new list(),注意list里的l是小寫的。也不需要導(dǎo)入包，這樣通過query.list()出來的list里存放的不再是默認(rèn)的Object數(shù)組了，而是List集合了
String hql = " select new list(name,passwd) from Users";
Query query = session.createQuery(hql);
//默認(rèn)查詢出來的list里存放的是一個Object數(shù)組，但是在這里list里存放的不再是默認(rèn)的Object數(shù)組了，而是List集合了
List<List> list = query.list();
for(List user : list){
String name = (String)user.get(0);
String passwd = (String)user.get(1);
System.out.println(name + " : " + passwd);
}
要注意的是，假如這時有些列是為空的話，則String hql = " select new list(name,passwd) from Users"; 是會報(bào)錯的，要用下面的方法：
3 //查詢其中幾個字段,添加new map(),注意map里的m是小寫的。也不需要導(dǎo)入包，這樣通過query.list()出來的list里存放的不再是默認(rèn)的Object數(shù)組了，而是map集合了
String hql = " select new map(name,passwd) from Users";
Query query = session.createQuery(hql);
//默認(rèn)查詢出來的list里存放的是一個Object數(shù)組，但是在這里list里存放的不再是默認(rèn)的Object數(shù)組了，而是Map集合了
List<Map> list = query.list();
for(Map user : list){
//一條記錄里所有的字段值都是map里的一個元素,key是字符串0,1,2,3.，value是字段值 
//如果將hql改為：String hql = " select new map(name as username,passwd as password) from Users";,那么key將不是字符串0,1,2了，而是"username","password"了
String name = (String)user.get("0");//get("0");是get(key),注意:0,1,2是字符串，而不是整形
String passwd = (String)user.get("1");
System.out.println(name + " : " + passwd);
}
4 修改默認(rèn)查詢結(jié)果(query.list())不以O(shè)bject[]數(shù)組形式返回，以自定義類型返回
package com.domain;
public class MyUser {
private String username;
private String password;
//因?yàn)椋篠tring hql = " select new com.domain.MyUser(name,passwd) from Users";所以必須要有接受2個參數(shù)的構(gòu)造函數(shù)
public MyUser(String username,String password){
this.username = username;
this.password = password;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
//通過query.list()出來的list里存放的不再是默認(rèn)的Object數(shù)組了,而是自定義的類MyUser,必須加包名，String hql = "from Users";中的Users類也是必須加包名的，但是因?yàn)樵賃sers.hbm.xml里<hibernate-mapping auto-import="true"> auto-import默認(rèn)值為true（所以auto-import屬性也可以不寫）,自動導(dǎo)入了
String hql = " select new com.domain.MyUser(name,passwd) from Users";
Query query = session.createQuery(hql);
//默認(rèn)查詢出來的list里存放的是一個Object數(shù)組，但是在這里list里存放的不再是默認(rèn)的Object數(shù)組了，而是MyUser對象了
List<MyUser> myUsers = query.list();
for(MyUser myUser : myUsers){
String name = myUser.getUsername();
String passwd = myUser.getPassword();
System.out.println(name + " : " + passwd);
}
5 條件查詢
//條件查詢，參數(shù)索引值從0開始，索引位置。通過setString,setParameter設(shè)置參數(shù)
String hql = "from Users where name=? and passwd=?";
Query query = session.createQuery(hql);
//第1種方式
// query.setString(0, "name1");
// query.setString(1, "password1");
//第2種方式
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());
}
//條件查詢，自定義索引名(參數(shù)名):username,:password.通過setString,setParameter設(shè)置參數(shù)
String hql = "from Users where name=:username and passwd=:password";
Query query = session.createQuery(hql);
//第1種方式
// query.setString("username", "name1");
// query.setString("password", "password1");
//第2種方式,第3個參數(shù)確定類型
query.setParameter("username", "name1",Hibernate.STRING);
query.setParameter("password", "password1",Hibernate.STRING);
List<Users> list = query.list();
for(Users users : list){
System.out.println(users.getId());
}
//條件查詢,通過setProperties設(shè)置參數(shù)
String hql = "from Users where name=:username and passwd=:password";
Query query = session.createQuery(hql);
//MyUser類的2個屬性必須和:username和:password對應(yīng)
MyUser myUser = new MyUser("name1","password1");
query.setProperties(myUser);
List<Users> list = query.list();
for(Users users : list){
System.out.println(users.getId());
}
假如覺得還是想用回原生SQL的話，可以這樣：
Query query = getSessionFactory().getCurrentSession().createSQLQuery(hql).addScalar("title",Hibernate.STRING).addScalar("id",Hibernate.INTEGER).setResultTransformer(Transformers.aliasToBean(Article.class));
就是要注意的話，這里的createSQLQuery里面跟的是原生的sql，要讀什么屬性，就要不斷加addScalar，個人覺得這個方式十分麻煩，呵呵
