springboot+swagger dao中方法报错

[YYpawn]

threw exception [Request processing failed; nested exception is org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.yy.springbootswagger.dao.UserDao.selectById] with root cause

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.yy.springbootswagger.dao.UserDao.selectById
at org.apache.ibatis.binding.MapperMethod$SqlCommand.<init>(MapperMethod.java:225) ~[mybatis-3.4.5.jar:3.4.5]
at org.apache.ibatis.binding.MapperMethod.<init>(MapperMethod.java:48) ~[mybatis-3.4.5.jar:3.4.5]
at org.apache.ibatis.binding.MapperProxy.cachedMapperMethod(MapperProxy.java:65) ~[mybatis-3.4.5.jar:3.4.5]
at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:58) ~[mybatis-3.4.5.jar:3.4.5]

MapperScan配置了
dao中的方法名跟mapper里面是一样的（复制的），项目启动没报错，查询就报500