@echo off
set "dirname=%date:~,4%%date:~5,2%%date:~8,2%"
::通过 %date% 系统变量得到日期为"2013/05/22 周三"，%date:~,4% 表示取日期的前面4个字符就是年份
::%date:~5,2% 表示取日期第5个字符开始的2个字符就是月份，%date:~8,2% 这个就是日期。
set "path=D:\db"
set "mysqldump="C:\Program Files\MySQL\MySQL Server 5.5\bin\mysqldump.exe""
set "backuser=root"
set "backpass=root"
::echo %dirname%
::echo %path%
::echo %mysqldump%
::echo %path%%dirname%
if not exist %path%\%dirname% mkdir %path%\%dirname%

%mysqldump% --opt -u%backuser% -p%backpass% mysql > %path%\%dirname%\mysql.sql

::echo "Successfully"
exit