如果查询单个对象，Spring无法访问数据库数据

I'm trying to query a single object from the database and whenever I execute the app it throws a null pointer exception, but when I query the whole table and place it on a list, I am getting all the result so there is no problem with the configurations for I can access the database. here is the part of the code that throws error:I'm trying to query a single object from the da