产品表

create table product(

    id number(2) primary key,

    name varchar2(10)

);

书表

create table booktbl(

    id number(2) ,

    name    varchar2(10),

    pageCount    number(3),

    foreign key(id) references product(id)

);

create sequence book_seq

increment by 1

start with 1

nomaxvalue nominvalue nocache;

CREATE  TRIGGER book_trigger BEFORE

INSERT ON booktbl FOR EACH ROW WHEN(new.id is null)

begin

select book_seq.nextval into:new.id from dual;

end;

drop table  booktbl;

drop sequence book_seq;

brop trigger book_trigger;

服装表

create table clothestbl(

    id number(2) references product(id),

    name varchar2(10),

    closize number(5)

);

create sequence clothes_seq

increment by 1

start with 1

nomaxvalue nominvalue nocache;

CREATE TRIGGER clo_trigger

before

INSERT ON clothestbl

FOR EACH ROW

WHEN(new.id is null)

begin

select clothes_seq.nextval into:new.id from dual;

end;

drop table  clothestbl;

drop sequence clothes_seq;

brop trigger clo_trigger;

  <class name="com.amaker.extendmodel.Product" table="Product">

           <id name="id">

               <generator class="native"></generator>

           </id>

           <property name="name"></property>

            <joined-subclass name="com.amaker.extendmodel.Book" table="booktbl">

               <key column="id"></key>

               <property name="pageCount"></property>

           </joined-subclass> 

            <joined-subclass name="com.amaker.extendmodel.Clothes" table="clothestbl">

               <key column="id"></key>

               <property name="size" column="closize"></property>

           </joined-subclass>

   </class>