查询没有没有某种类型的班级的学生，可通过多声部过滤

mec-biz/src/main/resources/config/mybatis/ClassGroupMapper.xml

@@ -283,6 +283,7 @@
         <result column="id_" property="id"/>
         <result column="music_group_id_" property="musicGroupId"/>
         <result column="subject_id_list_" property="subjectIdList"/>
+        <result column="memo_" property="memo"/>
         <result column="name_" property="name"/>
         <result column="student_num_" property="studentNum"/>
         <result column="create_time_" property="createTime"/>