hibernate 链接Mysql数据库小案例
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <!-- 设置数据库驱动 --> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <!-- 设置数据库URL --> <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernatedem</property> <!-- 数据库用户名 --> <property name="hibernate.connection.username">root</property> <!-- 数据库密码 --> <property name="hibernate.connection.password"></property> <!-- 指定对应数据库的方言,hibernate为了更好适配各种关系数据库,针对每种数据库都指定了一个方言dialect --> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.hbm2ddl.auto">update</property> <!-- 映射文件 --> <mapping resource="bdqn/entity/User.hbm.xml"/> </session-factory> </hibernate-configuration>
编写实体类(User)
package bdqn.entity; import java.util.Date; /** * Created by guo on 2017/9/16. */ public class User { private Integer id; private String name; private String password; private Date createTime; private Date expireTime; 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 String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public Date getCreateTime() { return createTime; } public void setCreateTime(Date createTime) { this.createTime = createTime; } public Date getExpireTime() { return expireTime; } public void setExpireTime(Date expireTime) { this.expireTime = expireTime; } } 编写小配置文件(User.hbm.xml文件)
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernaate.net/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping package="bdqn.entity"> <class name="User"> <id name="id"> <!-- 算法的核心思想是结合机器的网卡、当地时间、一个随机数来生成GUID --> <generator class="native"></generator> </id> <property name="name" column="name"></property> <property name="password" column="password"></property> <property name="createTime" type="date" column="createTime"></property> <property name="expireTime" type="date" column="expireTime"></property> </class> </hibernate-mapping>
编写测试类ExportDB
import bdqn.entity.User; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import java.util.List; /** * Created by guo on 2017/9/16. */ public class ExportDB { public static void main(String[] args) { //默认读取hibernate.cfg.xml文件 Configuration cfg = new Configuration().configure("Hibernate.cfg.xml"); SessionFactory factory = cfg.buildSessionFactory(); Session session = factory.openSession(); //查询 Query query = session.createQuery("from User"); List list = query.list(); System.out.println(list.size()); //添加 /*User user=new User(); user.setPassword("hahas"); user.setName("hahas"); session.save(user); session.beginTransaction().commit();*/ //删除 /* User user=new User(); user.setId(2); session.delete(user); session.beginTransaction().commit();*/ //修改 /* User user = session.load(User.class, 3); user.setName("guohua"); session.update(user); session.beginTransaction().commit();*/ System.out.println("success!!!!!"); } }