利用 Hibernate 的 SchemaExport 根据对象建立数据库

野性酷女 2022-06-18 01:24 139阅读 0赞

1 . 首先准备好hibernate的基本配置文件（../src/hibernate.cfg.xml）

<?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">  
<hibernate-configuration>  
 <session-factory>  
   
 <property name="hibernate.connection.driver\_class">com.mysql.jdbc.Driver</property>  
 <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/itcast2</property>  
 <property name="hibernate.connection.username">root</property>   
 <property name="dialect">org.hibernate.dialect.MySQLDialect</property>  
 <property name="hibernate.show\_sql">true</property>  
 <property name="hibernate.hbm2ddl.auto">update</property>  
 <mapping resource="com/itcast/bean/product/ProductType.hbm.xml"/>  
  
 </session-factory>  
</hibernate-configuration>   
  
2.根据需求建立所需的对象文件以及hibernate 映射文件：

(1) ProductType.java

(2) ProductType.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.itcast.bean.product.ProductType" table="product\_type">  
<id name="productTypeId" column="product\_type\_id">  
<generator class="increment"/>  
</id>  
<property name="productTypeName" column="product\_type\_name" not-null="true" length="36"/>  
<property name="productTypeNote" column="product\_type\_note" length="36" />  
<property name="productTypeVisible" column="product\_type\_visible" not-null="true"/>  
<property name="productTypeParenttype" column="parent\_id" />  
  
</class>  
</hibernate-mapping>

3. 创建以下文件并运行就可成功生成数据库：

package com.itcast.util;  
  
import org.hibernate.cfg.Configuration;  
import org.hibernate.tool.hbm2ddl.SchemaExport;  
  
public class ExportDB \{  
  
public static void main(String\[\] args) \{  
//默认使用src目录下的hibernate.cfg.xml配置文件  
Configuration cfg = new Configuration().configure();  
SchemaExport export = new SchemaExport(cfg);  
export.create(true, true);  
\}  
  
\}