@echo off
set backhome=back
set year=%date:~0,4%
set month=%date:~5,2%
set day=%date:~8,2%
set mydate=%year%%month%%day%
set hhmmss=%time:~0,2%%time:~3,2%%time:~6,2%
if "%hhmmss:~0,1%"==" " set hhmmss=0%time:~1,1%%time:~3,2%%time:~6,2%
mkdir e:\%backhome%\%mydate%
echo ------------------------------------------------ >> e:\%backhome%\%mydate%\log.txt
echo start backup at %mydate%_%hhmmss% >> e:\%backhome%\%mydate%\log.txt
echo ------------------------------------------------ >> e:\%backhome%\%mydate%\log.txt
exp andacms/******@ORCL file=e:\%backhome%\%mydate%\andacms_%mydate%.dmp owner=andacms BUFFER=512000000 2>> e:\%backhome%\%mydate%\log.txt
echo ------------------------------------------------ >> e:\%backhome%\%mydate%\log.txt
set endyear=%date:~0,4%
set endmonth=%date:~5,2%
set endday=%date:~8,2%
set enddate=%endyear%%endmonth%%endday%
set endhhmmss=%time:~0,2%%time:~3,2%%time:~6,2%
if "%endhhmmss:~0,1%"==" " set endhhmmss=0%time:~1,1%%time:~3,2%%time:~6,2%
echo backup finished at %enddate%_%endhhmmss% >> e:\%backhome%\%mydate%\log.txt
echo ------------------------------------------------ >> e:\%backhome%\%mydate%\log.txt

rem 计算指定天数之前的日期
set DaysAgo=7
rem 假设系统日期的格式为yyyymmdd
call :DateToDays %date:~0,4% %date:~5,2% %date:~8,2% PassDays
set /a PassDays-=%DaysAgo%
call :DaysToDate %PassDays% DstYear DstMonth DstDay
set DstDate=%DstYear%%DstMonth%%DstDay%
if exist e:\%backhome%\%DstDate% (
echo 删除%DaysAgo%天前的数据：%DstDate% >>e:\%backhome%\%mydate%\log.txt
rmdir /s/q e:\%backhome%\%DstDate%
)
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