'*************************************************************************
'**模 块 名：frestoredatabase_a
'**描    述：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"
'**参数说明：
'**          sDataBasePath  恢复后的数据库存放目录
'**          sBackupNumber  是从那个备份号恢复
'**          sReplaceExist  指定是否覆盖已经存在的数据
'**说    明：引用Microsoft ActiveX Data Objects 2.x Library
'**创 建 人：邹建
'**日    期：2003年12月09日
'*************************************************************************
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,根据你的情况修改连接字符串
    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
   
    '关闭用户进程,防止其它用户正在使用数据库,导致数据恢复失败
    iSql = "select spid from master..sysprocesses where dbid=db_id('" & sDataBaseName & "')"
    iRe.Open iSql, iDb, adOpenKeyset, adLockReadOnly
    While iRe.EOF = False
        iSql = "kill " & iRe(0)
        iDb.Execute iSql
        iRe.MoveNext
    Wend
    iRe.Close
   
    '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_a = iReturn
End Function