Exception in thread "main" org.apache.ibatis.exceptions.PersistenceException:
### Error querying database. Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for mapper.selectOne1
### Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for mapper.selectOne1
解决办法：
selectOne(a,b)函数中 a为mapper.xml中的namespace+所选的id b为传入的参数
其余可能的错误为mapper.xml中方法与namespace文件中方法不一致