目录解决方式拓展一:mysql导出scv文件乱码、蹿行拓展二:这是因为编码问题,我们将xls或者是xlsx转换为 CSV格式后,编码并不是UTF-8,导致存放到数据库的数据就会出现乱码问题
i want to cast from upper class pointer to lower class i.e from the base class pointer to derived class pointer.