Hibernate通过实体类与hbm创建表

Hibernate通过实体类与hbm.xml创建表

开始尝试了很多次，都没能成功创建表，问题在于

<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
or
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

生成的语句不同(见6)

老版本的MySQL使用TYPE而不是ENGINE（例如，TYPE = MYISAM）。MySQL 5.1为向下兼容而支持这个语法，但TYPE现在被轻视，而ENGINE是首先的用法。

MySQLDialect ->“type=MyISAM”

MySQL5Dialect->“engine=MyISAM”

项目结构

创建实体类

Student.java

public class Student implements Serializable {
    private int id;
    private String name;
    private int age;
	...//getter setter
}

创建映射

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="learn.hibernate.entity.Student" table="stu_tab" >
        <id name="id" column="stu_id">
            <generator class="native"/>
        </id>
        <property name="name" column="stu_name"/>
        <property name="age" column="stu_age"/>
    </class>
</hibernate-mapping>

配置

hibernate.cfg.xml

<hibernate-configuration>
    <session-factory>
        
        <!--配置数据库连接-->
        <property name="connection.url">jdbc:mysql://localhost:3306/test</property>
        <property name="connection.driver_class">com.mysql.cj.jdbc.Driver</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>

        <property name="connection.username">root</property>
        <property name="connection.password">123</property>
      
        <!--显示sql语句-->
        <property name="show_sql">true</property>
        <property name="format_sql">true</property>
      
        <!--设置映射-->   
        <mapping resource="learn/hibernate/entity/Student.hbm.xml"/>
        <!-- DB schema will be updated if needed -->
        <!-- <property name="hbm2ddl.auto">update</property> -->
    </session-factory>
</hibernate-configuration>

测试类

StudentTest.java

public class StudentTest {
    //测试在数据库中根据Student类以及Student.hbm.xml创建表
    @Test
    public void createTable(){
        ServiceRegistry sr = new StandardServiceRegistryBuilder().configure().build();
        Metadata md=new MetadataSources(sr).buildMetadata();
        SchemaExport se=new SchemaExport();
        se.create(EnumSet.of(TargetType.DATABASE), md);
    }
}

控制台输出

MySQL5Dialect

<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>

可以成功创建表，语句如下

Hibernate: 
    drop table if exists stu_tab

Hibernate: 
    create table stu_tab (
       stu_id integer not null auto_increment,
        stu_name varchar(255),
        stu_age integer,
        primary key (stu_id)
    ) engine=MyISAM

MySQLDialect

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

无法创建，语句如下

Hibernate: 
    drop table if exists stu_tab

Hibernate: 
    create table stu_tab (
       stu_id integer not null auto_increment,
        stu_name varchar(255),
        stu_age integer,
        primary key (stu_id)
    ) type=MyISAM

Hibernate通过实体类与hbm创建表

Hibernate通过实体类与hbm.xml创建表

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