Error querying database. Cause: java.sql.SQLException: Access denied for user ‘${jdbc.username}‘@‘lo

Error querying database. Cause: java.sql.SQLException: Access denied for user ‘${jdbc.username’@‘localhost’ (using password: YES)

The error may exist in com/mapper/UserMapper.xml

The error may involve com.mapper.UserMapper.selectUserAll

The error occurred while executing a query

所以，写代码的时候一定要注意注意再注意，这种写漏了的情况有的时候真的很难瞅见，也挺折磨人的