set filename=D:\dbbackup\cwsp\cwsp%date:~0,4%%date:~5,2%%date:~8,2%.dmp
set logname=D:\dbbackup\cwsp\cwsp%date:~0,4%%date:~5,2%%date:~8,2%.log
exp cwsp/cwsp@QDS_CS file=%filename% log=%logname% owner=cwsp

@echo off
::如果演示结果无误，把del前面的echo去掉，即可实现真正删除。
rem 指定待删除文件的存放路径
set SrcDir=D:\dbbackup\cwsp
set DaysAgo=7
call :DateToDays %date:~0,4% %date:~5,2% %date:~8,2% PassDays
set /a PassDays-=%DaysAgo%

call :DaysToDate %PassDays% DstYear DstMonth DstDay
set DstDate=cwsp%DstYear%%DstMonth%%DstDay%.dmp
for /f "delims=/" %%a in ('dir /b /a-d "%SrcDir%\cwsp????????.dmp"') do (
  if "%%a" leq "%DstDate%" (
    echo del /a /f /q "%SrcDir%\%%a"
  )
)
pause
goto :eof

:DateToDays %yy% %mm% %dd% days
setlocal ENABLEEXTENSIONS
set yy=%1&set mm=%2&set dd=%3
if 1%yy% LSS 200 if 1%yy% LSS 170 (set yy=20%yy%) else (set yy=19%yy%)

set /a dd=100%dd%%%100,mm=100%mm%%%100
set /a z=14-mm,z/=12,y=yy+4800-z,m=mm+12*z-3,j=153*m+2
set /a j=j/5+dd+y*365+y/4-y/100+y/400-2472633
endlocal&set %4=%j%&goto :EOF

:DaysToDate %days% yy mm dd
setlocal ENABLEEXTENSIONS
set /a a=%1+2472632,b=4*a+3,b/=146097,c=-b*146097,c/=4,c+=a
set /a d=4*c+3,d/=1461,e=-1461*d,e/=4,e+=c,m=5*e+2,m/=153,dd=153*m+2,dd/=5
set /a dd=-dd+e+1,mm=-m/10,mm*=12,mm+=m+3,yy=b*100+d-4800+m/10
(if %mm% LSS 10 set mm=0%mm%)&(if %dd% LSS 10 set dd=0%dd%)
endlocal&set %2=%yy%&set %3=%mm%&set %4=%dd%&goto :EOF

?功能：

??????? 备份当天数据库数据；

??????? 删除7天前的数据(包括>7天的数据)。