关于数据库的备份与恢复的问题

[JeanLaw]

请问如何在程序中用语句实现数据库的备份与恢复？

[gxhwq]

'*********************************************************
'* 名称：BackupDatabase
'* 功能：备份数据库
'* 控件：一个文本框和两个按钮（备份到和确定）
'*********************************************************
Public Sub BackupDatabase()
Dim cn As New ADODB.Connection
Dim s_path, s_dataexport As String
s_path = App.Path
Me.MousePointer = 11 '设置鼠标指针形状
'student1是需要备份的数据库名称
s_dataexport = "backup database student1 to disk='" + CommonDialog1.FileName + "'"
cn.Open "driver={sql server};server=" & d1 & ";database=student1;persist security info=false; userid=sa" '数据库连接字符串
'这里不需要连接master数据库，即可完成备份
cn.BeginTrans
cn.Execute s_dataexport
Err.Number = 0
If Err.Number = 0 Then
cn.CommitTrans
MsgBox "数据备份成功！", vbInformation, "提示"
MsgBox "数据备份文件存放路径:" & CommonDialog1.FileName, vbOKOnly, "提示"
Unload Me
Else
cn.RollbackTrans
MsgBox "数据备份失败！请检查数据库是否正在打开！", vbCritical, "提示"
End If
cn.Close
Set cn = Nothing
Me.MousePointer = 1
End Sub



'*********************************************************
'* 名称：RestoreDataBase
'* 功能：还原数据库
'* 控件：一个文本框和两个按钮（ 打开和确定）
'*********************************************************
Public Sub RestoreDataBase()
If Text1.Text = "" Then
MsgBox "请选择要恢复的数据文件！", vbInformation, "提示"
Exit Sub
Else
ret = MsgBox("数据恢复操作将会覆盖以前的所有数据并且覆盖后无法恢复，您确定要进行恢复操作吗？", vbQuestion + vbOKCancel, "提示")
If ret = vbOK Then
Dim cn As New ADODB.Connection
Dim sn As New ADODB.Recordset
Dim s_restore As String
Me.MousePointer = 11
cn.Open "Provider=SQLOLEDB.1;Persist Security Info=False;server=" & d1 & ";Initial Catalog=master;Data Source=127.0.0.1;user id=sa;password=" & d3 & ""
sn.Open "select spid from sysprocesses where dbid=db_id('student1')", cn
Do While Not sn.EOF
cn.Execute "kill " & sn("spid")
sn.MoveNext
Loop
sn.Close
s_restore = "restore database student1 from disk='" + Trim(Text1.Text) + "' with REPLACE"
cn.Execute s_restore
'Debug.Print gs_conn_string
'此时需要连接master数据库才能完成数据恢复操作
'同上student1为需要恢复的数据库
s_restore = "restore database student1 from disk='" + Trim(Text1.Text) + "'"
'text1一个用于记录需要恢复文件的地址的textbox
cn.Execute s_restore
cn.BeginTrans
If Err.Number = 0 Then
cn.CommitTrans
MsgBox "数据恢复成功！", vbInformation, "提示"
Command1.Enabled = True
Label1.Visible = False
Else
cn.RollbackTrans
MsgBox "数据恢复失败！", vbCritical, "提示"
Command1.Enabled = True
End If
cn.Close
Set cn = Nothing
Me.MousePointer = 1
Else
Exit Sub
End If
On Error Resume Next
Dim DBC As New DataBaseConnection
If db.State = 1 Then
db.Close
End If
db.ConnectionString = DBC.SqlConnectString(d1, d2, d3)
rs.CursorType = adOpenDynamic
rs.CursorLocation = adUseClient
rs.LockType = adLockOptimistic
db.CursorLocation = adUseClient
db.Open
Set cmd.ActiveConnection = db
If Err.Number Then
MsgBox Err.Description, 16 + vbOKOnly, Err.Number
Exit Sub
End If
db.DefaultDatabase = "student1"
If Err.Number Then
MsgBox Err.Description, 16 + vbOKOnly, Err.Number
Exit Sub
End If
End If
End Sub

[JeanLaw]

好详细，先谢谢了！

[yijiansong]

XUEXI

[dnvihc]

请问gxhwq(Buger)能帮我详细解释一下下面的那段话吗？
On Error Resume Next
Dim DBC As New DataBaseConnection
If db.State = 1 Then
db.Close
End If
db.ConnectionString = DBC.SqlConnectString(d1, d2, d3)
rs.CursorType = adOpenDynamic
rs.CursorLocation = adUseClient
rs.LockType = adLockOptimistic
db.CursorLocation = adUseClient
db.Open
Set cmd.ActiveConnection = db
If Err.Number Then
MsgBox Err.Description, 16 + vbOKOnly, Err.Number
Exit Sub
End If
db.DefaultDatabase = "student1"
If Err.Number Then
MsgBox Err.Description, 16 + vbOKOnly, Err.Number
Exit Sub
End If

[zjcxc]

'恢复数据库,返回出错信息,正常恢复,返回""
'调用:frestoredatabase_a "备份文件名","数据库名"
Public Function fRestoreDatabase_a(ByVal sBackUpfileName$ _
, ByVal sDataBaseName$ _
, Optional ByVal sDataBasePath$ = "" _
, Optional ByVal sBackupNumber& = 1 _
, Optional ByVal sReplaceExist As Boolean = False _
) As String

Dim iDb As ADODB.Connection, iRe As ADODB.Recordset
Dim iConcStr$, iSql$, iReturn$, iI&

'On Error GoTo lbErr

'创建对象
Set iDb = New ADODB.Connection
Set iRe = New ADODB.Recordset

'连接数据库服务器
iConcStr = "Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Data Source=zj"
iDb.Open iConcStr

'得到还原后的数据库存放目录,如果没有指定,存放到SQL SERVER的DATA目录
If sDataBasePath = "" Then
iSql = "select filename from master..sysfiles"
iRe.Open iSql, iDb, adOpenKeyset, adLockReadOnly
iSql = iRe(0)
iRe.Close
sDataBasePath = Left(iSql, InStrRev(iSql, "\"))
End If

'检查数据库是否存在
If sReplaceExist = False Then
iSql = "select 1 from master..sysdatabases where name='" & sDataBaseName & "'"
iRe.Open iSql, iDb, adOpenKeyset, adLockReadOnly
If iRe.EOF = False Then
iReturn = "数据库已经存在!"
iRe.Close
GoTo lbExit
End If
iRe.Close
End If

'获取数据库恢复信息
iSql = "restore filelistonly from disk='" & sBackUpfileName & "'" & vbCrLf & _
"with file=" & sBackupNumber
iRe.Open iSql, iDb, adOpenKeyset, adLockReadOnly

'生成数据库恢复语句
iSql = "restore database [" & sDataBaseName & "]" & vbCrLf & _
"from disk='" & sBackUpfileName & "'" & vbCrLf & _
"with file=" & sBackupNumber & vbCrLf
With iRe
While Not .EOF
iReturn = iRe("PhysicalName")
iI = InStrRev(iReturn, ".")
iReturn = IIf(iI = 0, "", Mid(iReturn, iI)) & "'"
iSql = iSql & ",move '" & iRe("LogicalName") & _
"' to '" & sDataBasePath & sDataBaseName & iReturn & vbCrLf
.MoveNext
Wend
.Close
End With
iSql = iSql & IIf(sReplaceExist, ",replace", "")

iDb.Execute iSql
iReturn = ""
GoTo lbExit

lbErr:
iReturn = Error
lbExit:
fRestoreDatabase = iReturn
End Function