通过实体类及映射文件生成数据库表

时间:2021-01-02 08:24:33

待实体类及映射文件生成后,进行如下操作:

1、在hibernate.cfg.xml配置文件中配置数据源、表生成属性及映射文件信息

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>
    <session-factory>
        <property name="myeclipse.connection.profile">
            com.mysql.jdbc.Driver
        </property>
        <property name="connection.url">
            jdbc:mysql://192.0.0.0:3306/databaseName
        </property>
        <property name="connection.username">root</property>
        <property name="connection.password">****</property>
        <property name="connection.driver_class">
            com.mysql.jdbc.Driver
        </property>
        <property name="dialect">
            org.hibernate.dialect.MySQLDialect
        </property>
        <property name="show_sql">true</property>   
<!-- auto schema export --> <property name="hibernate.hbm2ddl.auto">update</property> <mapping resource="com/prochanges/framework/domain/hbm/Addressbook.hbm.xml" /> <mapping      ......

</session-factory>
</hibernate-configuration>

2、编写hbm2ddl工具类,将实体类生成数据库表,运行如下main方法即可

package com.hutton;

import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;

public class GenerateDatabaseTable
{

    /**
     * @param args
     */
    public static void main(String[] args)
    {
        //read the config file
        Configuration conf = new Configuration().configure();
        SchemaExport export = new SchemaExport(conf);
        export.create(true, true);
    }

}

相关属性信息可参见:

  D:\...\hibernate-3.2\etc\hibernate.properties文件

#hibernate.hbm2ddl.auto create-drop  根据你的model类来生成表,但是每次运行都会删除上一次的表,重新生成表,哪怕2次没有任何改变
#hibernate.hbm2ddl.auto create 根据model类生成表,但是sessionFactory一关闭,表就自动删除
#hibernate.hbm2ddl.auto update 最常用的属性,也根据model类生成表,即使表结构改变了,表中的行仍然存在,不会删除以前的行
#hibernate.hbm2ddl.auto validate  只会和数据库中的表进行比较,不会创建新表,但是会插入新值