PowerShell应用之-批量还原数据库(支持完整，差异，事务日志)

开始

直接切入主题，今天我们继续来描述PowerShell的一个应用，实现批量还原SQL Server数据库,可以支持SQL Server 2005\2008数据库。在本章中，我们将涉及到几个要点：

Microsoft.SqlServer.Management.Smo.Restore类
System.Data.DataTable类
PowerShell中的函数(Function)
PowerShell命令Get-Unique

Microsoft.SqlServer.Management.Smo.Restore类

在PowerShell要实现还原SQL Server数据库，我们需要应用到Microsoft.SqlServer.Management.Smo.Restore类。它为我们提供了丰富的还原数据库过程需要的各种属性和方法。首先，提供一份数据库备份文件，我们要还原它，我们需要知道备份文件的标头信息(backup header information),和备份文件里组成(数据文件&日志文件)(the database and log files contained in the backup set)

要是在SQL Server Management Studio(SSMS)里，直接可以调用Transact-SQL:

[code]use master
go
Restore Headeronly From Disk='E:\DBBackup\myDB2008_20111107_01.trn'
Restore filelistonly From Disk='E:\DBBackup\myDB2008_20111107_01.trn'

View Code <#===========================================#>
##还原数据库

$serverInstance="WINSERVER01\SQL2008DE01"
$userName="sa"
$password="sql20081"

$Path="E:\DBBackup\"

$DBList=""
$RestorePath="E:\DATA\SQL2008DE01\"
$StopAt="2011-11-8 18:28:00" #还原到至时间点 [DateTime]

<#===========================================#>

[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo") | Out-Null
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.ConnectionInfo") | Out-Null
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoExtended") | Out-Null
[System.Reflection.Assembly]::LoadWithPartialName("System.Data") | Out-Null

$ServerConnection =new-object "Microsoft.SqlServer.Management.Common.ServerConnection" $serverInstance,$userName, $password

$ReadBackupHeader=New-Object "System.Data.DataTable"
$ReadBackupHeader.Columns.Add("DatabaseName","String") |Out-Null
$ReadBackupHeader.Columns.Add("BackupType","Int16") |Out-Null
$ReadBackupHeader.Columns.Add("BackupStartDate","DateTime") |Out-Null
$ReadBackupHeader.Columns.Add("BakFile","String") |Out-Null
$ReadBackupHeader.Columns.Add("NoRecovery","Boolean") |Out-Null
$ReadBackupHeader.Columns.Add("Position","Int16") |Out-Null

$ReadFileList=New-Object "System.Data.DataTable"
$ReadFileList.Columns.Add("DatabaseName","String") |Out-Null
$ReadFileList.Columns.Add("LogicalName","String") |Out-Null
$ReadFileList.Columns.Add("PhysicalName","String") |Out-Null
$ReadFileList.Columns.Add("Type","String") |Out-Null
$ReadFileList.Columns.Add("FileId","Int16") |Out-Null
$ReadFileList.Columns.Add("BakFile","String") |Out-Null
$ReadFileList.Columns.Add("FileNumber","Int16") |Out-Null

#--------------------------------------
#检查备份数据库清单
#--------------------------------------
Function CheckDB
{
Param([String]$DBvar)

Begin
{
[Boolean]$CheckResult=$false
}
Process
{
If($DBList -eq "")
{
$CheckResult=$true
}
Else
{
Foreach($x In $DBList.Split(","))
{
If($x -eq $DBvar)
{
$CheckResult=$true
Break
}
}
}
}
End
{
Return $CheckResult
}
}

#--------------------------------------
#还原数据库函数
#--------------------------------------
Function RestoreDB
{

begin
{
[Boolean]$ExecResult=$False
}
Process
{

$rowsBackupHeader=$ReadBackupHeader.Select("DatabaseName='"+$db+"'","BackupStartDate Asc")
If ($rowsBackupHeader)
{
Foreach($rowBackupHeader In $rowsBackupHeader)
{

$File=$rowBackupHeader["BakFile"]
$BackupType=$rowBackupHeader["BackupType"]
$rowsFileList=$ReadFileList.Select("BakFile='"+$File+"' And FileNumber="+$rowBackupHeader["Position"])

$Restore.Devices.Clear()
$Restore.RelocateFiles.Clear()

$Restore.Database=$db
$Restore.Devices.AddDevice($File, [Microsoft.SqlServer.Management.Smo.DeviceType]::File)
$Restore.ReplaceDatabase=$true
$Restore.KeepReplication=$False #不保留同步设置
$Restore.NoRecovery=$rowBackupHeader["NoRecovery"]
$Restore.FileNumber=$rowBackupHeader["Position"]

If ($BackupType -eq 2 ) #事务日志
{
$Restore.Action="Log"
$Restore.ToPointInTime=$(if($StopAt -gt $rowBackupHeader["BackupStartDate"]){$null} Else {$StopAt})
}
Else
{
$Restore.Action="Database"
$Restore.ToPointInTime=$null
}

foreach($rowFileList In $rowsFileList)
{
$logicalFileName=$rowFileList["LogicalName"]
If ($rowFileList.Type -eq "D")
{
$physicalFileName=$RestorePath+$logicalFileName+".mdf"
}
ElseIf ($rowFileList.Type -eq "L")
{
$physicalFileName=$RestorePath+$logicalFileName+".ldf"
}
$Restore.RelocateFiles.Add((New-Object "Microsoft.SqlServer.Management.Smo.RelocateFile" $logicalFileName,$physicalFileName)) |Out-Null

}

#清除正在当前数据库的进程
$Server.KillAllProcesses($db)

#执行还原动作
$Restore.SqlRestore($Server)
$Restore.Wait()
Write-Host "已还原数据库. DataBase:" $DB "`t`.FileNumber=" $Restore.FileNumber "`tBakFile: " $File
$ExecResult=$True
}

}
Else
{
Write-Warning "在数据库 $DB .没有可还原的备份文件。"
}

}
End
{
Return $ExecResult
}
}

#--------------------------------------
#过滤备份文件
#--------------------------------------
Function FilterDB
{
#完整
$tmpRows1=$ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=1 And BackupStartDate<='"+$StopAt+"'","BackupStartDate Desc")
[DateTime]$tmpDate="1900-01-01"

if ($tmpRows1)
{
$tmpRow=$tmpRows1[0]
$tmpDate=$tmpRow["BackupStartDate"]
Foreach($row In $ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=1 And BakFile<>'"+$tmpRow["BakFile"]+"'"))
{
$row.Delete()
}
}
Else
{
Foreach($row In $ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=1"))
{
$row.Delete()
}
}

#差异
$tmpRows5=$ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=5 And BackupStartDate<='"+$StopAt+"' And BackupStartDate>'"+$tmpDate+"' ","BackupStartDate Desc")
if ($tmpRows1 -and $tmpRows5)
{
$tmpRow=$tmpRows5[0]
Foreach($row In $ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=5 And BakFile<>'"+$tmpRow["BakFile"]+"'"))
{
$row.Delete()
}
}
Else
{
Foreach($row In $ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=5"))
{
$row.Delete()
}
}

#事务日志
$tmpRows2=$ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=2 And BackupStartDate>='"+$StopAt+"'","BackupStartDate Asc")
if ($tmpRows1 -and $tmpRows2)
{

$tmpRow=$tmpRows2[0]
Foreach($row In $ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=2 And BackupStartDate>='"+$StopAt+"' And BakFile<>'"+$tmpRow["BakFile"]+"'"))
{
$row.Delete()
}
}ElseIf($tmpRows1)
{

Foreach($row In $ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=2 And BackupStartDate<='"+$tmpDate+"'"))
{
$row.Delete()
#$ReadBackupHeader | Format-Table -AutoSize -Wrap
}
}
Else
{
Foreach($row In $ReadBackupHeader.Select("DatabaseName='"+$db+"' And BackupType=2"))
{
$row.Delete()
}
}

#结束对DataTable的编辑
$ReadBackupHeader.AcceptChanges()

#设置NoRecovery
$tmpRows=$ReadBackupHeader.Select("DatabaseName='"+$db+"'","BackupStartDate Desc")
If($tmpRows)
{$tmpRows[0]["NoRecovery"]=$false}

}

#--------------------------------------
Try
{
$ServerConnection.Connect()
}
Catch
{
Write-Error $_
}

if($ServerConnection.IsOpen)
{

Try
{
$Server=new-object "Microsoft.SqlServer.Management.Smo.Server" $ServerConnection
$Restore=new-object "Microsoft.SqlServer.Management.Smo.Restore"

$StopAt=$(If($StopAt -eq ""){"3000-12-31"}Else{[DateTime]$StopAt})

$Path=$Path+$(If($($Path.Split("\"))[-1] -eq "" ){""} Else {"\"})

$RestorePath=$(If($RestorePath -eq ""){$Server.Settings.DefaultFile}Else{$RestorePath}) #数据库文件默认路径(数据&日志文件同一路径)
$RestorePath=$RestorePath+$(If($($RestorePath.Split("\"))[-1] -eq "" ){""} Else {"\"})

Foreach($Bak In Get-ChildItem -Path $Path | Where-Object -FilterScript {$_.Mode -eq "-a---"}) #遍历备份文件夹
{
$File=$Path+$Bak.Name
$Restore.Devices.Clear()
$Restore.Devices.AddDevice($File, [Microsoft.SqlServer.Management.Smo.DeviceType]::File)
$Restore.FileNumber=0
$Read=$Restore.ReadBackupHeader($Server)
Foreach ($row In $Read)
{
$newRow =$ReadBackupHeader.NewRow();
$newRow["DatabaseName"]=$row["DatabaseName"]
$newRow["BackupType"]=$row["BackupType"]
$newRow["BackupStartDate"]=$row["BackupStartDate"]
$newRow["BakFile"]=$File
$newRow["NoRecovery"]=$true
$newRow["Position"]=$row["Position"]
$ReadBackupHeader.Rows.Add($newRow)

$DBName=$row["DatabaseName"]
$Restore.FileNumber=$row["Position"]
$FileRead=$Restore.ReadFileList($Server)
Foreach ($Filerow In $FileRead)
{
$FileNewRow =$ReadFileList.NewRow();
$FileNewRow["DatabaseName"]=$DBName
$FileNewRow["LogicalName"]=$Filerow["LogicalName"]
$FileNewRow["PhysicalName"]=$Filerow["PhysicalName"]
$FileNewRow["Type"]=$Filerow["Type"]
$FileNewRow["FileId"]=$Filerow["FileId"]
$FileNewRow["BakFile"]=$File
$FileNewRow["FileNumber"]=$Restore.FileNumber
$ReadFileList.Rows.Add($FileNewRow)
}
}

}

#结束对DataTable的编辑
$ReadBackupHeader.AcceptChanges()
$ReadFileList.AcceptChanges()

#遍历数据库
Foreach( $db In $(Foreach($Row In $ReadBackupHeader.rows){$Row["DatabaseName"]}) | Sort-Object | Get-Unique )
{
If(CheckDB($db) -eq $true) #检查备份数据库清单
{
#过滤备份
FilterDB

#还原数据库
$Result=RestoreDB

}
}
}
Catch
{
Write-Error $_
}

}





上面脚本能实现的是，在一个目录下存在着各个数据库的完整、差异、事务日志备份文件，可以根据设置“还原至时间点”还原某一个时间点的数据库。支持一个备份文件包含多个备份，支持自定义还原数据库清单。以上的脚本在PowerShell 2.0 + SQL Server2005+WinXP 和PowerShell 2.0 + SQL Server2008 R2+Windows Server 2008 R2 測試通過。

小結


本章我们描述了PowerShell2.0的一个应用，批量还原数据库，支持完整、差异、事务日志备份文件，并对其中的一些知识要点提取出来说明，让我们对PowerShell 2.0 有进一步的了解。在真实中，一些时候，特别是要在数据库后台批量处理一些任务，我们发觉PowerShell能为我们带来许多的方便。当然了，这里只是取1个批量的还原的例子，在实际的应用中，我们也许会碰到比当前例子更为复杂的情况，如页面还原、段落还原、联机还原等。可根据特定的场景，修改或编写更为复杂的脚本。