How to: Back Up Databases and Transaction Logs in Visual Basic .NET
This section describes how to back up and restore a database in Visual Basic under the simple recovery model.
The code example shows how to back up an existing database to a file and then how to restore it.
Backing up databases
Start Visual Studio 2005.
From the File menu, select New Project. The New Project dialog box appears.
In the Project Types pane, select Visual Basic. In the Templates pane, select Console Application.
(Optional) In the Name box, type the name of the new application.
Click OK to load the Visual Basic console application template.
On the Project menu, select Add Reference item. The Add Reference dialog box appears. Select Browse and locate the SMO assemblies in the C:\Program Files\Microsoft SQL Server\90\SDK\Assemblies folder. Select the following files:
Microsoft.SqlServer.ConnectionInfo.dll
Microsoft.SqlServer.Smo.dll
Microsoft.SqlServer.SqlEnum.dll
Microsoft.SqlServer.SmoEnum.dll
On the View menu, click Code.-Or-Select the Module1.vb window to display the code window.
In the code, before any declarations, type the following Imports statements to qualify the types in the SMO namespace:
Imports Microsoft.SqlServer.Management.Smo Imports Microsoft.SqlServer.Management.CommonInsert the code that follows this procedure into the main program.
Run and build the application.
示例
'Connect to the local, default instance of SQL Server.
Dim srv As Server
srv = New Server
'Reference the AdventureWorks database.
Dim db As Database
db = srv.Databases("AdventureWorks")
'Store the current recovery model in a variable.
Dim recoverymod As Integer
recoverymod = db.DatabaseOptions.RecoveryModel
'Define a Backup object variable.
Dim bk As New Backup
'Specify the type of backup, the description, the name, and the database to be backed up.
bk.Action = BackupActionType.Database
bk.BackupSetDescription = "Full backup of Adventureworks"
bk.BackupSetName = "AdventureWorks Backup"
bk.Database = "AdventureWorks"
'Declare a BackupDeviceItem by supplying the backup device file name in the constructor, and the type of device is a file.
Dim bdi As BackupDeviceItem
bdi = New BackupDeviceItem("Test_Full_Backup1", DeviceType.File)
'Add the device to the Backup object.
bk.Devices.Add(bdi)
'Set the Incremental property to False to specify that this is a full database backup.
bk.Incremental = False
'Set the expiration date.
Dim backupdate As New Date
backupdate = New Date(2006, 10, 5)
bk.ExpirationDate = backupdate
'Specify that the log must be truncated after the backup is complete.
bk.LogTruncation = BackupTruncateLogType.Truncate
'Run SqlBackup to perform the full database backup on the instance of SQL Server.
bk.SqlBackup(srv)
'Inform the user that the backup has been completed.
Console.WriteLine("Full Backup complete.")
'Remove the backup device from the Backup object.
bk.Devices.Remove(bdi)
'Make a change to the database, in this case, add a table called test_table.
Dim t As Table
t = New Table(db, "test_table")
Dim c As Column
c = New Column(t, "col", DataType.Int)
t.Columns.Add(c)
t.Create()
'Create another file device for the differential backup and add the Backup object.
Dim bdid As BackupDeviceItem
bdid = New BackupDeviceItem("Test_Differential_Backup1", DeviceType.File)
'Add the device to the Backup object.
bk.Devices.Add(bdid)
'Set the Incremental property to True for a differential backup.
bk.Incremental = True
'Run SqlBackup to perform the incremental database backup on the instance of SQL Server.
bk.SqlBackup(srv)
'Inform the user that the differential backup is complete.
Console.WriteLine("Differential Backup complete.")
'Remove the device from the Backup object.
bk.Devices.Remove(bdid)
'Delete the AdventureWorks database before restoring it.
srv.Databases("AdventureWorks").Drop()
'Define a Restore object variable.
Dim rs As Restore
rs = New Restore
'Set the NoRecovery property to true, so the transactions are not recovered.
rs.NoRecovery = True
'Add the device that contains the full database backup to the Restore object.
rs.Devices.Add(bdi)
'Specify the database name.
rs.Database = "AdventureWorks"
'Restore the full database backup with no recovery.
rs.SqlRestore(srv)
'Inform the user that the Full Database Restore is complete.
Console.WriteLine("Full Database Restore complete.")
'Remove the device from the Restore object.
rs.Devices.Remove(bdi)
'Set te NoRecovery property to False.
rs.NoRecovery = False
'Add the device that contains the differential backup to the Restore object.
rs.Devices.Add(bdid)
'Restore the differential database backup with recovery.
rs.SqlRestore(srv)
'Inform the user that the differential database restore is complete.
Console.WriteLine("Differential Database Restore complete.")
'Remove the device.
rs.Devices.Remove(bdid)
'Set the database recovery mode back to its original value.
srv.Databases("AdventureWorks").DatabaseOptions.RecoveryModel = recoverymod
'Drop the table that was added.
srv.Databases("AdventureWorks").Tables("test_table").Drop()
srv.Databases("AdventureWorks").Alter()
'Remove the backup files from the hard disk.
My.Computer.FileSystem.DeleteFile("C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Backup\Test_Full_Backup1")
My.Computer.FileSystem.DeleteFile("C:\Program Files\Microsoft SQL Server\MSSQL.1\MSSQL\Backup\Test_Differential_Backup1")
请参阅
概念
Backing Up and Restoring Databases and Transaction Logs