mybatis一对多

1.一对多：两次 查询

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.shangsheng.springbootservlet.user.dao.UserMapper" >
  <resultMap id="BaseResultMap" type="com.shangsheng.springbootservlet.user.entity.User" >
    <id column="id" property="id" jdbcType="INTEGER" />
    <result column="name" property="name" jdbcType="VARCHAR" />
    <result column="password" property="password" jdbcType="VARCHAR" />
    <result column="per_id" property="per_id" jdbcType="INTEGER"/>

  </resultMap>

  <select id="getUserList" resultMap="getList" parameterType="int">
    select id,name,password,per_id from user where id=#{id}
  </select>

  <resultMap id="getList" type="com.shangsheng.springbootservlet.user.entity.User">
    <collection property="persons" column="id" ofType="com.shangsheng.springbootservlet.user.entity.Person" select="getAll"/>
  </resultMap>

  <select id="getAll" resultMap="personResultMap">
    select person_id,sex,mark from person where person_id=#{person_id}
  </select>

  <resultMap id="personResultMap" type="com.shangsheng.springbootservlet.user.entity.Person">
    <id column="id" property="id" jdbcType="INTEGER" />
    <result column="sex" property="sex" jdbcType="VARCHAR" />
    <result column="mark" property="mark" jdbcType="BIGINT" />
  </resultMap>
②，一次查询：

<sql id="Base_Column_List" >
  id, name, password
</sql>

<sql id="good_Column_List">
  person_id,sex,mark
</sql>

<resultMap id="personResult" type="com.shangsheng.springbootservlet.user.entity.User" >
  <id column="id" property="id" jdbcType="INTEGER" />
  <result column="name" property="name" jdbcType="VARCHAR" />
  <result column="password" property="password" jdbcType="VARCHAR" />
  <collection property="personList" ofType="com.shangsheng.springbootservlet.user.entity.Person">
    <result column="person_id" property="personId" jdbcType="INTEGER" />
    <result column="sex" property="sex" jdbcType="VARCHAR" />
    <result column="mark" property="mark" jdbcType="BIGINT" />
  </collection>
</resultMap>

<select id="getAll" resultMap="personResult" parameterType="java.lang.Integer" >
  select
  <include refid="Base_Column_List" />,
  <include refid="good_Column_List" />
  from user join person on person_id=id
  and id = #{id,jdbcType=INTEGER}
</select>