求助：如何用命令方式恢复最新位置的SQL bak库，详细见内，多谢

[山水汕汕]

一个SQL备份库文件中存在多个位置的备份库，用命令恢复时需要指定file值，对应不同时期 备份的库，但是恢复前需要知道有几个位置，取最大值作为file参数，就可以恢复最近的备份库

restore database test from disk =‘D:\test.bak’
with file = 2,recovery,replace

现在想知道怎么用命令方式获取到bak文件中有几个位置，并怎么将最大值赋值给file，谢谢各位大神！

[道素]

IF OBJECT_ID('TempDB..#temp') IS NOT NULL DROP TABLE #temp
GO
CREATE TABLE #temp( 
BackupName NVARCHAR(128) 
,BackupDescription NVARCHAR(255) 
,BackupType smallint 
,ExpirationDate datetime 
,Compressed tinyint 
,Position smallint 
,DeviceType tinyint 
,UserName NVARCHAR(128) 
,ServerName NVARCHAR(128) 
,DatabaseName NVARCHAR(128) 
,DatabaseVersion INT 
,DatabaseCreationDate datetime 
,BackupSize numeric(20,0) 
,FirstLSN numeric(25,0) 
,LastLSN numeric(25,0) 
,CheckpointLSN numeric(25,0) 
,DatabaseBackupLSN numeric(25,0) 
,BackupStartDate datetime 
,BackupFinishDate datetime 
,SortOrder smallint 
,CodePage smallint 
,UnicodeLocaleId INT 
,UnicodeComparisonStyle INT 
,CompatibilityLevel tinyint 
,SoftwareVendorId INT 
,SoftwareVersionMajor INT 
,SoftwareVersionMinor INT 
,SoftwareVersionBuild INT 
,MachineName NVARCHAR(128) 
,Flags INT 
,BindingID uniqueidentifier 
,RecoveryForkID uniqueidentifier 
,Collation NVARCHAR(128) 
,FamilyGUID uniqueidentifier 
,HasBulkLoggedData INT 
,IsSnapshot INT 
,IsReadOnly INT 
,IsSingleUser INT 
,HasBackupChecksums INT 
,IsDamaged INT 
,BeginsLogChain INT 
,HasIncompleteMetaData INT 
,IsForceOffline INT 
,IsCopyOnly INT 
,FirstRecoveryForkID uniqueidentifier 
,ForkPointLSN numeric(25,0) 
,RecoveryModel NVARCHAR(128) 
,DifferentialBaseLSN numeric(25,0) 
,DifferentialBaseGUID uniqueidentifier 
,BackupTypeDescription NVARCHAR(128) 
,BackupSetGUID uniqueidentifier 
,CompressedBackupSize BIGINT 
,Containement INT

) 


 INSERT INTO #temp
 EXEC ('RESTORE HEADERONLY FROM DISK = ''f:\test.bak''')

DECLARE @position INT 
SELECT @position = MAX(position) FROM #temp WHERE BackupType = 1/*Full backup*/ AND BackupName = 'testdb-Full Database Backup'
RESTORE DATABASE AdventureWorks FROM DISK = 'f:\test.bak'
WITH  FILE = @position -- the max position/ use above variable