继承映射关系 subclass的查询

 Person大类的映射文件配置

1 <hibernate-mapping package="com.zh.hibernate.subclass">

     <class name="Person" table="PERSONS" discriminator-value="PERSONS">

         <id name="id" type="java.lang.Integer">
             <column name="ID" />
             <generator class="native" />
         </id>

        <discriminator column="TYPE" type="string"></discriminator>

         <property name="name" type="java.lang.String">
             <column name="NAME" />
         </property>

         <property name="age" type="java.lang.String">
             <column name="AGE" />
         </property>

            <subclass name="Student" discriminator-value="STUDENT">
                <property name="school" type="string" column="SCHOOL"></property>
            </subclass>

     </class>

 </hibernate-mapping>

查询语句的区别

Hibernate:
    select
        person0_.ID as ID1_0_0_,
        person0_.NAME as NAME3_0_0_,
        person0_.AGE as AGE4_0_0_,
        person0_.SCHOOL as SCHOOL5_0_0_,
        person0_.TYPE as TYPE2_0_0_
    from
        PERSONS person0_
    where
        person0_.ID=?
11, zzqq
Hibernate:
    select
        student0_.ID as ID1_0_0_,
        student0_.NAME as NAME3_0_0_,
        student0_.AGE as AGE4_0_0_,
        student0_.SCHOOL as SCHOOL5_0_0_
    from
        PERSONS student0_
    where
        student0_.ID=?
        and student0_.TYPE='STUDENT'