Caused by: org.apache.ibatis.exceptions.PersistenceException:
Error building SqlSession.
The error may exist in com/atguigu/dao/TeacherMapper.xml
Cause: org.apache.ibatis.builder.BuilderException: Error parsing SQL Mapper Configuration. Cause: java.lang.IllegalArgumentException: Mapped Statements collection already contains value for com.atguigu.dao.TeacherMapper.getTeacher. please check com/atguigu/dao/TeacherMapper.xml and com/atguigu/dao/TeacherMapper.java (best guess)
getTeacher方法同時寫了注解，和xml：删除自己不需要的即可
