毕业设计师在b站找了个教务管理系统的项目，具体的问题是所属专业这里不显示数据，我刷新了之后显示暂无数据，我能力有限实在不知道是哪里导致的bug，好像是只要涉及到这段类似功能的代码就不显示数据代码和报错如下：<select id="selectAll" resultType="com.example.entity.Classes">
select classes.*,teacher.name as teacherName,speciality.name as specialityName
from classes
left join teacher on classes.teacher_id = teacher.id
left join speciality on classes.speciality_id = speciality.id
<where>
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@5c513901]
<== Row: 1, 计算机科学与技术, 计算机科学与技术, null, 100, null
<== Total: 2
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@5a9a8067]
JDBC Connection [HikariProxyConnection@1980578057 wrapping com.mysql.cj.jdbc.ConnectionImpl@1efb3ff4] will not be managed by Spring
==> Preparing: SELECT count(0) FROM classes LEFT JOIN teacher ON classes.teacher_id = teacher.id LEFT JOIN speciality ON classes.speciality_id = speciality.id
==> Parameters:
<== Columns: count(0)
<== Row: 1
<== Total: 1
==> Preparing: select classes.*,teacher.name as teacherName,speciality.name as specialityName from classes left join teacher on classes.teacher_id = teacher.id left join speciality on classes.speciality_id = speciality.id order by id desc LIMIT ?
==> Parameters: 10(Integer)
<== Columns: id, name, content, teacher_id, speciality_id, teacherName, specialityName
<== Row: 2, 计算机科学技术1班, 计算机科学技术1班, 10, 1, 查宇, 计算机科学与技术
<== Total: 1
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@672e53b5]