以個(gè)普通Users表為例：
建表語句：
CREATE DATABASE `interceptor`
CHARACTER SET 'utf8';
USE `interceptor`;
DROP TABLE IF EXISTS `users`;
create table users(
id int auto_increment primary key,
name varchar(10) not null,
passwd varchar(10) not null
)
ENGINE=InnoDB DEFAULT CHARSET=utf8;
User.java:
package com.domain;
public class Users implements java.io.Serializable {
private Integer id;
private String name;
private String passwd;
public Users() {
}
public Users(String name, String passwd) {
this.name = name;
this.passwd = passwd;
}
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
public String getPasswd() {
return this.passwd;
}
public void setPasswd(String passwd) {
this.passwd = passwd;
}
User.hbm.xml:
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.domain.Users" table="users" catalog="interceptor">
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="native" />
</id>
<property name="name" type="java.lang.String">
<column name="name" length="10" not-null="true" />
</property>
<property name="passwd" type="java.lang.String">
<column name="passwd" length="10" not-null="true" />
</property>
</class>
</hibernate-mapping>
1. 查詢整個(gè)映射對象所有字段
//直接from查詢出來的是一個(gè)映射對象，即：查詢整個(gè)映射對象所有字段
String hql = "from Users";
Query query = session.createQuery(hql);
List<Users> users = query.list();
for(Users user : users){
System.out.println(user.getName() + " : " + user.getPasswd() + " : " + user.getId());
}
輸出結(jié)果為：
name1 : password1 : 1
name2 : password2 : 2
name3 : password3 : 3
2.查詢單個(gè)字段
//查詢單個(gè)字段
String hql = " select name from Users";
Query query = session.createQuery(hql);
List<String> list = query.list();
for(String str : list){
System.out.println(str);
}
輸出結(jié)果為：
name1
name2
name3
3.查詢其中幾個(gè)字段
//查詢其中幾個(gè)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(gè)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);
}
輸出結(jié)果為：
name1 : password1
name2 : password2
name3 : password3
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List形式返回
//查詢其中幾個(gè)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(gè)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);
}
/**
輸出結(jié)果為：
name1 : password1
name2 : password2
name3 : password3
*/
5.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Map形式返回
//查詢其中幾個(gè)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(gè)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(gè)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);
}
/**
輸出結(jié)果為：
name1 : password1
name2 : password2
name3 : password3
*/
6.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Set形式返回,但是因?yàn)镾et里是不允許有重復(fù)的元素，所以:username和password的值不能相同。只需將hql改為：String
hql = " select new set(name,passwd) from Users";
7.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
自定義類：
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(gè)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(dòng)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(gè)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);
}
/**
輸出結(jié)果為：
name1 : password1
name2 : password2
name3 : password3
*/
8：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(gè)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){
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(gè)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());
}