怎么用SQL语句备份和恢复数据库?

BACKUP DATABASE "mydb" TO DISK ='C:mybak.db' with init

RESTORE DATABASE "mydb" FROM DISK='C:mybak.db';

--完整备份
Backup Database NorthwindCS
To disk='G:BackupNorthwindCS_Full_20070908.bak'

--差异备份
Backup Database NorthwindCS
To disk='G:BackupNorthwindCS_Diff_20070908.bak'
With Differential

--日志备份，默认截断日志
Backup Log NorthwindCS
To disk='G:BackupNorthwindCS_Log_20070908.bak'

--日志备份，不截断日志
Backup Log NorthwindCS
To disk='G:BackupNorthwindCS_Log_20070908.bak'
With No_Truncate

--截断日志不保留
Backup Log NorthwindCS
With No_Log

--或者
Backup Log NorthwindCS
With Truncate_Only
--截断之后日志文件不会变小
--有必要可以进行收缩

--文件备份
Exec Sp_Helpdb NorthwindCS --查看数据文件
Backup Database NorthwindCS
File='NorthwindCS' --数据文件的逻辑名
To disk='G:BackupNorthwindCS_File_20070908.bak'

--文件组备份
Exec Sp_Helpdb NorthwindCS --查看数据文件
Backup Database NorthwindCS
FileGroup='Primary' --数据文件的逻辑名
To disk='G:BackupNorthwindCS_FileGroup_20070908.bak'
With init

--分割备份到多个目标
--恢复的时候不允许丢失任何一个目标
Backup Database NorthwindCS
To disk='G:BackupNorthwindCS_Full_1.bak'
,disk='G:BackupNorthwindCS_Full_2.bak'

--镜像备份
--每个目标都是相同的
Backup Database NorthwindCS
To disk='G:BackupNorthwindCS_Mirror_1.bak'
Mirror 
To disk='G:BackupNorthwindCS_Mirror_2.bak'
With Format --第一次做镜像备份的时候格式化目标

--镜像备份到本地和远程
Backup Database NorthwindCS
To disk='G:BackupNorthwindCS_Mirror_1.bak'
Mirror 
To disk='\192.168.1.200BackupNorthwindCS_Mirror_2.bak'
With Format

--每天生成一个备份文件
Declare @Path Nvarchar(2000)
Set @Path ='G:BackupNorthwindCS