mybatis返回新增对象的主键

加这两行就可以返回这个插入对象的自增的主键
<insert >
    insert into seating_portrait (
    system_producer
    ,system_type,
    system_processer,
    hostname,
    system_version,
    physical_memory,
    mac_addr,
    c_area,
    run_time,
    register_user,
    dongdong_dir_size,
    all_c_space,
    ost_file_size,
    disks,
    ip,
    c_used_rate ,
    sn,start_time
    ) values (
    #{system_producer}, #{system_type},#{system_processer},#{hostname},#{system_version},#{physical_memory},#{mac_addr},
    #{c_area},#{run_time},#{register_user},#{dongdong_dir_size},#{all_c_space},#{ost_file_size},#{disks},#{ip}
    ,#{c_used_rate},#{sn},#{start_time}
    )
</insert>