<insert id="addPerson" parameterType="orm.Person" keyProperty="id" useGeneratedKeys="true">

    insert into Person (name,age,gender) values (#{name},#{age},#{gender})

</insert>

SqlSession session =DBUtils.getSqlSession();

Person p=new Person();

p.setName("caoyc");

p.setAge((byte));

p.setGender("男");

System.out.println(session.insert("orm.personMapper.addPerson",p));;

session.commit();

session.close();

System.out.println(p.getId());

<insert id="addPerson" parameterType="orm.Person" >

    <selectKey resultType="java.long.Integer" keyProperty="id" order="BEFORE">

        select  idauto.nextval from dual

    </selectKey>

    insert into Person (id,name,age,gender) values (#{id},#{name},#{age},#{gender})

</insert>