collection 两张表查询

场景：

两张表：学生基础信息表A，学生成绩表B，两张表通过userId关联

返回结果：以学生为维度返回列表，学生有一个外部属性：成绩列表

语文 100 张三 u001 成绩 数学 99 英语 88 李四 u002 成绩 语文 66 数学 77 英语 99 王五 u003 成绩 语文 22 数学 55 英语 33 Mapper.xml

<?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.user.mapper.read.UserReaderMapper" > <resultMap id="BaseResultMap" type="com.user.pojo.UserPojo" > <id column="id" property="id" jdbcType="INTEGER" /> <result column="user_id" property="userId" jdbcType="VARCHAR" /> <result column="user_name" property="userName" jdbcType="VARCHAR" /> <collection property="scorePojos" column="user_id" select="queryUserScoreList" /> </resultMap> <resultMap id="UserScoreResultMap" type="com.user.pojo.UserScorePojo" > <result column="user_id" property="userId" jdbcType="VARCHAR" /> <result column="subject" property="subject" jdbcType="VARCHAR" /> <result column="score" property="score" jdbcType="VARCHAR" /> </resultMap> <sql id="Base_Column_List" > id, user_id, user_name </sql> <select id="queryUserList" resultMap="BaseResultMap" parameterType="com.user.param.UserQueryParam" > select <include refid="Base_Column_List" /> from user_table where 1=1 <if test="userId!=null and userId!='' "> AND (user_id = #{userId,jdbcType=VARCHAR} ) </if> <if test="userName!=null and userName!='' "> AND (user_name = #{userName,jdbcType=VARCHAR} ) </if> </select> <select id="queryUserScoreList" resultMap="UserScoreResultMap" parameterType="com.user.param.UserQueryParam" > select subject, score ,user_id from user_score_table </select> </mapper> Mapper.java

public interface UserReaderMapper extends BaseReaderMapper{ List<UserPojo> queryUserList(UserQueryParam param); }