SQl自动备份删除

BackupEveryDay
每天进行数据库的差异备份
day
Declare @File Varchar(2000)
Set @File='E:\Databasebackup\njyc_data_diff.BAK'
Backup database njyc_data to Disk=@File with DIFFERENTIAL
WeekBackup
每周进行一次数据库的完全备份，备份文件名为当天日期 （njyc_data_年_月_日）
BackupAll
DECLARE @BackupFile Varchar(256)
SET @BackupFile='E:\Databasebackup\'
SET @BackupFile=@BackupFile+'njyc_data_'+Replace(convert(varchar(10),getdate(),120),'-','_')
Backup DataBase njyc_data to Disk=@BackupFile with Init
BackupDiffrent
DECLARE @BackupFile Varchar(256)
SET @BackupFile='E:\Databasebackup\'
SET @BackupFile=@BackupFile+'njyc_data_diff.bak'
Backup DataBase njyc_data to Disk=@BackupFile with Init
EveryWeek
DeleteLastmonth
--判断文件是否存在
create table ##tb(a bit,b bit,c bit)
DECLARE @DelFile Varchar(256)
set @DelFile='E:\Databasebackup\'
set @DelFile=@DelFile+'njyc_data_'+Replace(convert(varchar(10),getdate()-28,120),'-','_')
insert into ##tb
exec master..xp_fileexist @DelFile
--文件存在则删除
if exists(select 1 from ##tb where a=1)
begin
DECLARE @Delsql Varchar(256)
set @Delsql='Del '+ @DelFile
Exec  master..xp_cmdshell  @Delsql
end
drop table ##tb