hibernate,中文意思是冬眠。是完全实现ORM的框架。
创建数据表PERSON:
CREATE TABLE `person` (
`ID` int(11) NOT NULL,
`NAME` varchar(255) CHARACTER SET utf8 DEFAULT NULL,
`GENDER` char(1) CHARACTER SET utf8 DEFAULT NULL,
`AGE` int(11) DEFAULT NULL,
`PROVINCE` varchar(255) CHARACTER SET utf8 DEFAULT NULL,
PRIMARY KEY (`ID`)
)
实体类:
public class Person {
private Integer id;
private String name;
private Character gender;
private Integer age;
private String province;
...
}
在pom.xml加入jar包依赖:
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>3.6.10.Final</version>
</dependency>
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.20.0-GA</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-nop</artifactId>
<version>1.6.4</version>
</dependency>
hibernate.cfg.xml(位于Maven项目的src/main/resources目录下)
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">
org.hibernate.dialect.MySQLDialect<!-- 数据库方法配置, hibernate在运行的时候,会根据不同的方言生成符合当前数据库语法的sql -->
</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8</property><!-- 在xml的文件中,我们需要将"&"做转义"&" -->
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">123456</property>
<!-- 在控制台 显示hibernate在运行时候执行的sql语句 -->
<property name="hibernate.show_sql">true</property>
<!-- 格式化sql -->
<property name="hibernate.format_sql">false</property>
<!--如果表不存在则自动建表 -->
<property name="hibernate.hbm2ddl.auto">update</property>
<mapping resource="com/guo/bean/Person.hbm.xml"/><!--映射文件-->
</session-factory>
</hibernate-configuration>
Person.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="com.guo.bean.Person" table="PERSON">
<id name="id" column="ID" type="int">
<generator class="assigned"/> <!--主键自定义-->
<!-- <generator class="identity"/> 主键自增长 -->
</id>
<property name="name" column="NAME" type="java.lang.String"/>
<property name="gender" column="GENDER" type="java.lang.Character"/>
<property name="age" column="AGE" type="java.lang.Integer"/>
<property name="province" column="PROVINCE" type="java.lang.String"/>
</class>
</hibernate-mapping>
测试:
SessionFactory factory = new Configuration().configure().buildSessionFactory();//自动加载hibernate.cfg.xml
Session session = factory.openSession();
Transaction tx = session.beginTransaction();
try {
Person p = new Person(10,"杜甫",'男',55,"陕");
session.save(p);//保存到数据库
//生成的SQL语句:insert into PERSON (NAME, GENDER, AGE, PROVINCE, ID) values (?, ?, ?, ?, ?)
p.setAge(25);
p.setName("李贺");
session.update(p);//更新(必须要有主键)
//生成的SQL语句:update PERSON set NAME=?, GENDER=?, AGE=?, PROVINCE=? where ID=?
p = (Person) session.get(Person.class, 10);//主键查询
//生成的SQL:select person0_.ID as ID0_0_, person0_.NAME as NAME0_0_, person0_.GENDER as GENDER0_0_, person0_.AGE as AGE0_0_, person0_.PROVINCE as PROVINCE0_0_ from PERSON person0_ where person0_.ID=?
Person p1 = new Person(30, "杜甫", '男', 55, "陕");
session.saveOrUpdate(p1);//保存或更新(表未设置主键执行保存,反之执行更新;有主键则如果该主键存在更新,反之保存)
//生成的SQL:(两条)
//select person_.ID, person_.NAME as NAME0_, person_.GENDER as GENDER0_, person_.AGE as AGE0_, person_.PROVINCE as PROVINCE0_ from PERSON person_ where person_.ID=?
//insert into PERSON (NAME, GENDER, AGE, PROVINCE, ID) values (?, ?, ?, ?, ?)
session.delete(p);//删除
List<Person> personList = session.createCriteria(Person.class).list();//查询全部
} catch (Exception e) {
e.printStackTrace();
tx.rollback();//回滚
}finally {
tx.commit();//提交事务
session.close();
factory.close();
}