mybatis_04 resultType和resultMap区别

   <select id="findOrderExtbyId" parameterType="int" resultType="com.ahd.model.OrderExt">
    select
      o.*,u.username,u.address
    from
      `user` u,orders o
    where u.id=o.user_id
    and u.id=#{id}
   </select>

<resultMap id="userByresultmap" type="user">
    <id property="id" column="id_"></id>
    <result property="username" column="username_"></result>
    <result property="birthday" column="birthday_"></result>
    <result property="sex" column="sex_"></result>
    <result property="address" column="address_"></result>
</resultMap>
<select id="findUserByResultMap" parameterType="userQueryVO" resultMap="userByresultmap">
    select
      id id_,
      username username_,
      birthday birthday_,
      sex sex_,
      address address_
    from user where username like "%${user.username}%"
</select>