cooleshow/cooleshow-user/user-biz/src/main/resources/config/mybatis/UserBindingTeacherMapper.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.yonge.cooleshow.biz.dal.dao.UserBindingTeacherDao">

    <select id="myStudent" resultType="com.yonge.cooleshow.biz.dal.vo.CourseStudentVo">
        SELECT
        su.id_ AS userId,
        su.username_ AS userName,
        su.real_name_ AS realName,
        su.avatar_ AS avatar,
        su.phone_ AS phone,
        (SELECT group_concat(name_) FROM `subject` WHERE find_in_set(id_,s.subject_id_)) AS subjectName
        FROM user_binding_teacher b
        LEFT JOIN sys_user su ON b.student_id_=su.id_
        LEFT JOIN student s ON b.student_id_=s.user_id_
        <where>
            <if test="param.subjectId != null">
                find_in_set(#{param.subjectId},s.subject_id_)
            </if>
            <if test="param.userName !=null and param.userName !=''">
                AND su.username_ LIKE CONCAT('%', #{param.userName}, '%')
            </if>
        </where>
    </select>
</mapper>