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">
 2
 3     <class name="Person" table="PERSONS" discriminator-value="PERSONS">
 4
 5         <id name="id" type="java.lang.Integer">
 6             <column name="ID" />
 7             <generator class="native" />
 8         </id>
 9
10        <discriminator column="TYPE" type="string"></discriminator>
11
12         <property name="name" type="java.lang.String">
13             <column name="NAME" />
14         </property>
15
16         <property name="age" type="java.lang.String">
17             <column name="AGE" />
18         </property>
19
20            <subclass name="Student" discriminator-value="STUDENT">
21                <property name="school" type="string" column="SCHOOL"></property>
22            </subclass>
23
24     </class>
25
26 </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‘