准备
模型及映射文件
// 班级模型:com.zze.bean.Class
package com.zze.bean;
import java.util.HashSet;
import java.util.Set;
public class Class {
public Class() {
}
public Class(Integer id, String name) {
this.id = id;
this.name = name;
}
private Integer id;
private String name;
private Set<Student> students = new HashSet<>();
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Set<Student> getStudents() {
return students;
}
public void setStudents(Set<Student> students) {
this.students = students;
}
@Override
public String toString() {
return "Class{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}
}
<!-- 班级映射:com/zze/bean/Class.hbm.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.zze.bean.Class" table="class">
<id name="id">
<generator class="native"/>
</id>
<property name="name" length="32"/>
<set name="students" cascade="save-update">
<key column="cid"/>
<one-to-many class="com.zze.bean.Student"/>
</set>
</class>
</hibernate-mapping>
<!-- 学生模型:com.zze.bean.Student -->
package com.zze.bean;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;
public class Student {
public Student() {
}
public Student(Integer id, String name, Integer age,String gender) {
this.id = id;
this.name = name;
this.age = age;
this.gender = gender;
}
private Integer id;
private String name;
private Integer age;
private String gender;
private Class clazz;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public Class getClazz() {
return clazz;
}
public void setClazz(Class clazz) {
this.clazz = clazz;
}
@Override
public String toString() {
return "Student{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}
}
<!-- 学生映射:com/zze/bean/Student.hbm.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.zze.bean.Student" table="student">
<id name="id">
<generator class="native"/>
</id>
<property name="name" length="32"/>
<property name="age"/>
<property name="gender"/>
<many-to-one name="clazz" column="cid" class="com.zze.bean.Class"/>
</class>
</hibernate-mapping>
全局配置
<!-- hibernate.cfg.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://192.168.208.153:3306/1221</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">root</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.show_sql">true</property>
<property name="hibernate.format_sql">true</property>
<property name="current_session_context_class">thread</property>
<property name="hibernate.hbm2ddl.auto">create</property>
<mapping resource="com/zze/bean/Class.hbm.xml"></mapping>
<mapping resource="com/zze/bean/Student.hbm.xml"></mapping>
</session-factory>
</hibernate-configuration>
工具类
// com.zze.util.HibernateUtil
package com.zze.util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
public static final Configuration cfg;
public static final SessionFactory sf;
static {
cfg = new Configuration().configure();
sf = cfg.buildSessionFactory();
}
public static Session openSession() {
return sf.openSession();
}
public static Session getCurrentSession() {
return sf.getCurrentSession();
}
}
初始化数据
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Class clazz1 = new Class(null,"软件一班");
Class clazz2 = new Class(null,"软件二班");
Class clazz3 = new Class(null,"汽修一班");
Class clazz4 = new Class(null,"汽修二班");
Student student1 = new Student(null, "张三", 12,"男");
Student student2 = new Student(null, "李四", 13,"女");
Student student3 = new Student(null, "王五", 14,"男");
Student student4 = new Student(null, "赵六", 15,"男");
Student student5 = new Student(null, "吴刚", 39,"男");
Student student6 = new Student(null, "王如花", 30,"女");
Student student7 = new Student(null, "李志静", 49,"女");
Student student8 = new Student(null, "何王天", 30,"男");
clazz1.getStudents().add(student1);
clazz1.getStudents().add(student2);
clazz2.getStudents().add(student3);
clazz2.getStudents().add(student4);
clazz3.getStudents().add(student5);
clazz3.getStudents().add(student6);
clazz4.getStudents().add(student7);
clazz4.getStudents().add(student8);
session.save(clazz1);
session.save(clazz2);
session.save(clazz3);
session.save(clazz4);
transaction.commit();
几种检索方式
OID 检索
Hibernate 根据对象的 OID(主键)进行检索。
使用 get 方法
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Class clazz = session.get(Class.class, 1);
System.out.println(clazz);
transaction.commit();
/*
Hibernate:
select
class0_.id as id1_0_0_,
class0_.name as name2_0_0_
from
class class0_
where
class0_.id=?
Class{id=1, name='软件一班'}
*/
使用 load 方法
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Class clazz = session.load(Class.class, 1);
System.out.println(clazz);
transaction.commit();
/*
Hibernate:
select
class0_.id as id1_0_0_,
class0_.name as name2_0_0_
from
class class0_
where
class0_.id=?
Class{id=1, name='软件一班'}
*/
对象导航检索
Hibernate 根据一个已经查询到的对象,获得其关联的对象的一种查询方式。
导航查询
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Class clazz = session.load(Class.class, 1);
System.out.println(clazz);
System.out.println(Arrays.toString(clazz.getStudents().toArray()));
transaction.commit();
/*
Hibernate:
select
class0_.id as id1_0_0_,
class0_.name as name2_0_0_
from
class class0_
where
class0_.id=?
Class{id=1, name='软件一班'}
Hibernate:
select
students0_.cid as cid5_1_0_,
students0_.id as id1_1_0_,
students0_.id as id1_1_1_,
students0_.name as name2_1_1_,
students0_.age as age3_1_1_,
students0_.gender as gender4_1_1_,
students0_.cid as cid5_1_1_
from
student students0_
where
students0_.cid=?
[Student{id=2, name='张三'}, Student{id=1, name='李四'}]
*/
HQL检索
Hibernate Language Query,Hibernate 本身提供语法支持的一种检索方式。
简单查询 - 查询所有班级
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql ="from Class";
Query query = session.createQuery(hql);
List<Class> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
class0_.id as id1_0_,
class0_.name as name2_0_
from
class class0_
[Class{id=1, name='软件一班'}, Class{id=2, name='软件二班'}, Class{id=3, name='汽修一班'}, Class{id=4, name='汽修二班'}]
*/
别名查询
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql ="select c from Class c";
Query query = session.createQuery(hql);
List<Class> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
class0_.id as id1_0_,
class0_.name as name2_0_
from
class class0_
[Class{id=1, name='软件一班'}, Class{id=2, name='软件二班'}, Class{id=3, name='汽修一班'}, Class{id=4, name='汽修二班'}]
*/
排序查询 - 根据年龄排序
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
// 升序
String hql = "from Student order by age";
// 降序
// String hql = "from Student order by age desc";
Query query = session.createQuery(hql);
List<Class> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
student0_.id as id1_1_,
student0_.name as name2_1_,
student0_.age as age3_1_,
student0_.gender as gender4_1_,
student0_.cid as cid5_1_
from
student student0_
order by
student0_.age
[Student{id=2, name='张三'}, Student{id=1, name='李四'}, Student{id=3, name='王五'}, Student{id=4, name='赵六'}, Student{id=6, name='王如花'}, Student{id=8, name='何王天'}, Student{id=5, name='吴刚'}, Student{id=7, name='李志静'}]
*/
条件查询
1、一个条件,查询 name='张三'
的 Student。
Transaction transaction = session.beginTransaction();
// 参数按位置绑定
String hql = "from Student where name = ?";
Query query = session.createQuery(hql);
query.setParameter(0, "张三");
List<Student> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
student0_.id as id1_1_,
student0_.name as name2_1_,
student0_.age as age3_1_,
student0_.gender as gender4_1_,
student0_.cid as cid5_1_
from
student student0_
where
student0_.name=?
[Student{id=2, name='张三'}]
*/
2、多个条件 - 查询 name
中包含 '王'
且 age
大于 18
的 Student。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "from Student where name like :name and age>:age";
Query query = session.createQuery(hql);
query.setParameter("name", "%王%");
query.setParameter("age", 18);
List<Student> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
student0_.id as id1_1_,
student0_.name as name2_1_,
student0_.age as age3_1_,
student0_.gender as gender4_1_,
student0_.cid as cid5_1_
from
student student0_
where
(
student0_.name like ?
)
and student0_.age>?
[Student{id=6, name='王如花'}, Student{id=8, name='何王天'}]
*/
投影查询
1、查询单个属性,返回 List<Object>
。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "select s.name from Student s";
Query query = session.createQuery(hql);
List<Object> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
student0_.name as col_0_0_
from
student student0_
[李四, 张三, 王五, 赵六, 吴刚, 王如花, 李志静, 何王天]
*/
2、查询多个属性,返回 List<Object[]>
。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "select s.name,s.age from Student s";
Query query = session.createQuery(hql);
List<Object[]> list = query.list();
for (Object[] objects : list) {
System.out.println(Arrays.toString(objects));
}
transaction.commit();
/*
Hibernate:
select
student0_.name as col_0_0_,
student0_.age as col_1_0_
from
student student0_
[李四, 13]
[张三, 12]
[王五, 14]
[赵六, 15]
[吴刚, 39]
[王如花, 30]
[李志静, 49]
[何王天, 30]
*/
3、查询多个属性,返回 List<Class>
。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
/*
需要让模型提供对应构造:
public Student(String name, Integer age) {
this.name = name;
this.age = age;
}
*/
String hql = "select new Student(name,age) from Student";
Query query = session.createQuery(hql);
List<Student> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
student0_.name as col_0_0_,
student0_.age as col_1_0_
from
student student0_
[Student{id=null, name='李四'}, Student{id=null, name='张三'}, Student{id=null, name='王五'}, Student{id=null, name='赵六'}, Student{id=null, name='吴刚'}, Student{id=null, name='王如花'}, Student{id=null, name='李志静'}, Student{id=null, name='何王天'}]
*/
分页查询
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "from Student";
Query query = session.createQuery(hql);
query.setFirstResult(0); // 起始行索引
query.setMaxResults(3); // 每页条数
List<Student> list = query.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
student0_.id as id1_1_,
student0_.name as name2_1_,
student0_.age as age3_1_,
student0_.gender as gender4_1_,
student0_.cid as cid5_1_
from
student student0_ limit ?
[Student{id=1, name='李四'}, Student{id=2, name='张三'}, Student{id=3, name='王五'}]
Process finished with exit code 0
*/
聚合查询
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
// 聚合函数使用 count max min avg sum
String hql = "select count(1) from Student";
Query query = session.createQuery(hql);
Object o = query.uniqueResult();
System.out.println(o.getClass());
System.out.println(o);
transaction.commit();
/*
Hibernate:
select
count(1) as col_0_0_
from
student student0_
class java.lang.Long
8
*/
分组查询
根据 gender
分组,查询每个 gender
的对应数据条数,返回 List<Object[]>
。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "select gender,count(1) from Student group by gender";
Query query = session.createQuery(hql);
List<Object[]> list = query.list();
for (Object[] objects : list) {
System.out.println(Arrays.toString(objects));
}
transaction.commit();
/*
Hibernate:
select
student0_.gender as col_0_0_,
count(1) as col_1_0_
from
student student0_
group by
student0_.gender
[女, 3]
[男, 5]
*/
普通内连接
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "from Student c join c.clazz";
Query query = session.createQuery(hql);
List<Object[]> list = query.list();
for (Object[] objects : list) {
System.out.println(Arrays.toString(objects));
}
transaction.commit();
/*
Hibernate:
select
student0_.id as id1_1_0_,
class1_.id as id1_0_1_,
student0_.name as name2_1_0_,
student0_.age as age3_1_0_,
student0_.gender as gender4_1_0_,
student0_.cid as cid5_1_0_,
class1_.name as name2_0_1_
from
student student0_
inner join
class class1_
on student0_.cid=class1_.id
[Student{id=1, name='李四'}, Class{id=1, name='软件一班'}]
[Student{id=2, name='张三'}, Class{id=1, name='软件一班'}]
[Student{id=3, name='王五'}, Class{id=2, name='软件二班'}]
[Student{id=4, name='赵六'}, Class{id=2, name='软件二班'}]
[Student{id=5, name='吴刚'}, Class{id=3, name='汽修一班'}]
[Student{id=6, name='王如花'}, Class{id=3, name='汽修一班'}]
[Student{id=7, name='李志静'}, Class{id=4, name='汽修二班'}]
[Student{id=8, name='何王天'}, Class{id=4, name='汽修二班'}]
*/
迫切内连接
迫切内连接: 其实就是在普通的内连接 inner join
后添加关键字 fetch
,将关联表数据封装到查询对象的属性中。
1、查询所有学生及其班级。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "from Student c join fetch c.clazz";
Query query = session.createQuery(hql);
List<Student> list = query.list();
for (Student student : list) {
System.out.println(String.format("%s %s", student, student.getClazz()));
}
transaction.commit();
/*
Hibernate:
select
student0_.id as id1_1_0_,
class1_.id as id1_0_1_,
student0_.name as name2_1_0_,
student0_.age as age3_1_0_,
student0_.gender as gender4_1_0_,
student0_.cid as cid5_1_0_,
class1_.name as name2_0_1_
from
student student0_
inner join
class class1_
on student0_.cid=class1_.id
Student{id=1, name='李四'} Class{id=1, name='软件一班'}
Student{id=2, name='张三'} Class{id=1, name='软件一班'}
Student{id=3, name='王五'} Class{id=2, name='软件二班'}
Student{id=4, name='赵六'} Class{id=2, name='软件二班'}
Student{id=5, name='吴刚'} Class{id=3, name='汽修一班'}
Student{id=6, name='王如花'} Class{id=3, name='汽修一班'}
Student{id=7, name='李志静'} Class{id=4, name='汽修二班'}
Student{id=8, name='何王天'} Class{id=4, name='汽修二班'}
*/
2、查询所有班级以及属于该班级的学生。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String hql = "select distinct c from Class c join fetch c.students";
Query query = session.createQuery(hql);
List<Class> list = query.list();
for (Class clazz : list) {
System.out.println(String.format("%s %s", clazz, clazz.getStudents()));
}
transaction.commit();
/*
Class{id=1, name='软件一班'} [Student{id=2, name='张三'}, Student{id=1, name='李四'}]
Class{id=2, name='软件二班'} [Student{id=4, name='赵六'}, Student{id=3, name='王五'}]
Class{id=3, name='汽修一班'} [Student{id=5, name='吴刚'}, Student{id=6, name='王如花'}]
Class{id=4, name='汽修二班'} [Student{id=7, name='李志静'}, Student{id=8, name='何王天'}]
*/
QBC检索
Query By Criteria,条件查询,是一种更加面向对象化的查询方式。
简单查询
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Class.class);
List<Class> list = criteria.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
this_.id as id1_0_0_,
this_.name as name2_0_0_
from
class this_
[Class{id=1, name='软件一班'}, Class{id=2, name='软件二班'}, Class{id=3, name='汽修一班'}, Class{id=4, name='汽修二班'}]
*/
排序查询
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Class.class);
// 升序
criteria.addOrder(Order.asc("id"));
// 降序
// criteria.addOrder(Order.desc("id"));
List<Class> list = criteria.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
this_.id as id1_0_0_,
this_.name as name2_0_0_
from
class this_
order by
this_.id asc
[Class{id=1, name='软件一班'}, Class{id=2, name='软件二班'}, Class{id=3, name='汽修一班'}, Class{id=4, name='汽修二班'}]
*/
分页查询
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Student.class);
criteria.setFirstResult(0); // 数据起始索引
criteria.setMaxResults(2); // 每页数据条数
List<Student> list = criteria.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
this_.id as id1_1_0_,
this_.name as name2_1_0_,
this_.age as age3_1_0_,
this_.gender as gender4_1_0_,
this_.cid as cid5_1_0_
from
student this_ limit ?
[Student{id=1, name='李四'}, Student{id=2, name='张三'}]
*/
条件查询
1、简单 and
条件查询 - 查询 name
包含 '王'
且 age>10
的学生。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Student.class);
// 默认多个 criteria.add 的条件是用 and 连接
criteria.add(Restrictions.like("name", "%王%"));
criteria.add(Restrictions.gt("age", 10));
List<Student> list = criteria.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
this_.id as id1_1_0_,
this_.name as name2_1_0_,
this_.age as age3_1_0_,
this_.gender as gender4_1_0_,
this_.cid as cid5_1_0_
from
student this_
where
this_.name like ?
and this_.age>?
[Student{id=3, name='王五'}, Student{id=6, name='王如花'}, Student{id=8, name='何王天'}]
*/
2、简单 or
条件查询 - 查询 name
包含 '王'
或 name
包含 '张'
的学生。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Student.class);
// or 条件可以通过 Restrictions.or 方法实现
criteria.add(Restrictions.or(Restrictions.like("name", "%王%"), Restrictions.like("name", "%张%")));
List<Student> list = criteria.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
this_.id as id1_1_0_,
this_.name as name2_1_0_,
this_.age as age3_1_0_,
this_.gender as gender4_1_0_,
this_.cid as cid5_1_0_
from
student this_
where
(
this_.name like ?
or this_.name like ?
)
[Student{id=2, name='张三'}, Student{id=3, name='王五'}, Student{id=6, name='王如花'}, Student{id=8, name='何王天'}]
*/
3、复杂 and
和 or
查询 - 查询 (name
包含 '王'
且 age>10
) 或 name
包含 '张'
的学生。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Student.class);
// 通过 conjunction.add 添加的条件是 and 连接
Conjunction conjunction = Restrictions.conjunction();
conjunction.add(Restrictions.like("name", "%王%"));
conjunction.add(Restrictions.gt("age", 10));
// 通过 disjunction.add 添加的条件是 or 连接
Disjunction disjunction = Restrictions.disjunction();
disjunction.add(conjunction);
disjunction.add(Restrictions.like("name", "%张%"));
criteria.add(disjunction);
List<Student> list = criteria.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
this_.id as id1_1_0_,
this_.name as name2_1_0_,
this_.age as age3_1_0_,
this_.gender as gender4_1_0_,
this_.cid as cid5_1_0_
from
student this_
where
(
(
this_.name like ?
and this_.age>?
)
or this_.name like ?
)
[Student{id=2, name='张三'}, Student{id=3, name='王五'}, Student{id=6, name='王如花'}, Student{id=8, name='何王天'}]
*/
聚合及分组统计查询
统计男女人数及最大年龄。
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = session.createCriteria(Student.class);
/*
criteria :
add : 普通条件,where
addOrder : 排序
setProjection : 聚合函数和 group by having
*/
ProjectionList projectionList = Projections.projectionList();
projectionList.add(Projections.groupProperty("gender"));
projectionList.add(Projections.rowCount());
projectionList.add(Projections.max("age"));
criteria.setProjection(projectionList);
List<Object[]> list = criteria.list();
for (Object[] objects : list) {
System.out.println(Arrays.toString(objects));
}
transaction.commit();
/*
Hibernate:
select
this_.gender as y0_,
count(*) as y1_,
max(this_.age) as y2_
from
student this_
group by
this_.gender
[女, 3, 49]
[男, 5, 39]
*/
离线条件查询
查询 name
包含 '一'
的班级。
DetachedCriteria detachedCriteria = DetachedCriteria.forClass(Class.class);
detachedCriteria.add(Restrictions.like("name", "%一%"));
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
Criteria criteria = detachedCriteria.getExecutableCriteria(session);
List<Class> list = criteria.list();
System.out.println(list);
transaction.commit();
/*
Hibernate:
select
this_.id as id1_0_0_,
this_.name as name2_0_0_
from
class this_
where
this_.name like ?
[Class{id=1, name='软件一班'}, Class{id=3, name='汽修一班'}]
*/
SQL 检索
Hibernate 支持的原生 SQL 查询。
SQL 查询返回 List<Object>
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String sql = "select * from class";
SQLQuery sqlQuery = session.createSQLQuery(sql);
List<Object[]> list = sqlQuery.list();
for (Object[] objects : list) {
System.out.println(Arrays.toString(objects));
}
transaction.commit();
/*
Hibernate:
select
*
from
class
[1, 软件一班]
[2, 软件二班]
[3, 汽修一班]
[4, 汽修二班]
*/
SQL 查询返回 List<Class>
Session session = HibernateUtil.getCurrentSession();
Transaction transaction = session.beginTransaction();
String sql = "select * from class";
SQLQuery sqlQuery = session.createSQLQuery(sql);
sqlQuery.addEntity(Class.class);
List<Class> list = sqlQuery.list();
for (Class clazz : list) {
System.out.println(clazz);
}
transaction.commit();
/*
Hibernate:
select
*
from
class
Class{id=1, name='软件一班'}
Class{id=2, name='软件二班'}
Class{id=3, name='汽修一班'}
Class{id=4, name='汽修二班'}
*/
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