怎么实现ACCESS数据库的备份与恢复，谢谢大家！

Question

最好能提供源码参考！

Answer 1

未证实-----------------------------------------------------------
用压缩/恢复数据库方法来实现Access数据库备份：unit unAccessTools;interfaceuses Sysutils,ComObj,Dialogs;function DaoActive(var DaoObject:OleVariant):Boolean;
function DaoCompactDB(const FileName:string):Boolean;
function DaoRepairDB(const FileName:string):Boolean;implementationfunction DaoActive(var DaoObject:OleVariant):Boolean;
begin
  Result:=False;
  try
    DaoObject:=GetActiveOleObject('DAO.DBEngine.36');
    Result:=True;
  except
    try
      DaoObject:=CreateOleObject('DAO.DBEngine.36');
      Result:=True;
    except
      DaoObject:=Null;
    end;
  end;
end;//压缩Access数据库
function DaoCompactDB(const FileName:string):Boolean;
var
  db:OleVariant;
  TempFile:string;
begin
  Result:=False;
  try
    if not DaoActive(db) then
      Exit;
    try
      TempFile:=ExtractFilePath(FileName)+'msaTemp.mdb';
      db.CompactDatabase(FileName,TempFile);
      DeleteFile(FileName);
      RenameFile(TempFile,FileName);
      Result:=True;
    except
      on E:EOleException do
        ShowMessage(E.Message);
    end
  finally
    db:=Unassigned;
  end;
end;//修复Access数据库
function DaoRepairDB(const FileName:string):Boolean;
var
  db:OleVariant;
begin
  Result:=False;
  try
    if not DaoActive(db) then
      Exit;
    try
      db.RepairDatabase(FileName);
      Result:=True;
    except
      on E:EOleException do
        ShowMessage(E.Message);
    end
  finally
    db:=Unassigned;
  end;
end;end.

Answer 2

无论压缩、解压，但是者是一个文件的Copy-paster的过程，用FileCopyTO实现。----------------
沉沦中..........

Answer 3

to WWWWA(aaaa):谢谢你！
我用了 COPYFILE这个函数，可是没有拷过去呀！

Answer 4

to  netcha(只喝茶) :谢谢你！

Answer 5

to  amei2000go(浪子) :谢谢你！怎么压缩加密，能不能提供例子代码？

Answer 6

////////////////////////////////////////////////////////////////////////////////
// 功能     : 压缩数据
// 参数     :
// CompressionLevel: 压缩比
// SourceStream: 数据源
// TargetStream: 目标数据源
// 返回值   : 是否成功
// 日期     : 2002/7/12
////////////////////////////////////////////////////////////////////////////////
function CompressStream(const CompressionLevel: TCompressionLevel;SourceStream:TMemoryStream;var TargetStream:TMemoryStream):boolean;
var
    ComStream:TCompressionStream;
    Count:integer;
begin
    ComStream:=TCompressionStream.Create(CompressionLevel,TargetStream);
    try
        Count := SourceStream.Size;        SourceStream.SaveToStream(ComStream);
        ComStream.Free;
        SourceStream.Clear;
        //写入原始图像的尺寸
        SourceStream.WriteBuffer(Count, SizeOf(Count));
        //写入经过压缩的图像流
        SourceStream.CopyFrom(TargetStream,0);        TargetStream.Clear;
        SourceStream.SaveToStream(TargetStream);        result:=true;
    except
        result:=false;
    end;
end;////////////////////////////////////////////////////////////////////////////////
// 功能     : 解压缩数据
// 参数     :
// SourceStream: 数据源
// TargetStream: 目标数据源
// 返回值   : 是否成功
// 日期     : 2002/7/12
////////////////////////////////////////////////////////////////////////////////
function DeCompressStream(SourceStream:TMemoryStream;var TargetStream:TMemoryStream):boolean;
var
    ComStream:TDecompressionStream;
    TempStream:TMemoryStream;
    FStream:TMemoryStream;
    Count:integer;
    Buffer: PChar;
    B:PChar;
begin
    FStream:=TMemoryStream.Create;
    TempStream:=TMemoryStream.Create;
    try
        try
            TempStream.LoadFromStream(SourceStream);
            // 将长度去掉
            TempStream.ReadBuffer(Count, SizeOf(Count));            GetMem(B,TempStream.Size-SizeOf(Count));            TempStream.ReadBuffer(B^,TempStream.Size-SizeOf(Count));
            TargetStream.WriteBuffer(B^,TempStream.Size-SizeOf(Count));
            FreeMem(B);            TempStream.Clear;
            TempStream.CopyFrom(TargetStream,0);            TargetStream.Clear;            FStream.LoadFromStream(TempStream);            ComStream:=TDecompressionStream.Create(FStream);            GetMem(Buffer, Count);
            ComStream.ReadBuffer(Buffer^,Count);
            TargetStream.WriteBuffer(Buffer^, Count);
            TargetStream.Position := 0;//复位流指针            FreeMem(Buffer);            result:=true;
        except
            result:=false;
        end;
    finally
        FStream.Free;
        TempStream.Free;
    end;
end;

Answer 7

关于程序的声明，你可以参考Ｄｅｌｐｈｉ　的光盘，又一个ZLib的示例，你可以看看！上面是我改装的代码。

Answer 8

unit DBConnection;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  Db, ADODB, Access2000;type
  TdmDBConnection = class(TDataModule)
    adocAccess: TADOConnection;
    adsGetSysParam: TADODataSet;
    adsCAInfo: TADODataSet;
    procedure DataModuleCreate(Sender: TObject);
    procedure DataModuleDestroy(Sender: TObject);
  private
    { Private declarations }  public
    { Public declarations }    AccessMaster: TAccessApplication;    sDataPath: String;    procedure GetSysParam(const pSection_ID, pIdent: string; var sParam: string);    procedure SetSysParam(const pSection_ID, pIdent: string; sParam: string);    procedure ConnectDB(MDBName: String);    function PackDB(DBFileName: String): String;    function CompactMDB(sSourceDB: String): String;  end;var
  dmDBConnection: TdmDBConnection;implementation
uses Registry, FileCtrl, JRO_TLB, uSysCommon, uSysSecCom;{$R *.DFM}procedure TdmDBConnection.GetSysParam(const pSection_ID, pIdent: string; var sParam: string);
begin
  if not adocAccess.Connected then ConnectDB('SysReg.mdb');
  with adsGetSysParam do
  begin
    if Active then
      Close;
    Parameters.ParamByName('Section_ID').Value := pSection_ID;
    Parameters.ParamByName('Ident').Value := pIdent;
    Open;
    if not EOF then
      sParam := FieldByName('Params').AsString
    else
      sParam := EmptyStr;
  //  ShowMessage(sParam);
    Close;
  end;
end;function TdmDBConnection.PackDB(DBFileName: String): String;
const
  sProvider = 'Provider=Microsoft.Jet.OLEDB.4.0;';
var
  IJetEng: JetEngine;
  sOldMDB, sNewMDB, sTempFile, sErr: String;
begin
  sErr := '';
  sTempFile := ExtractFileDir(Application.ExeName) + '\TmpAccessDB01.mdb';  if FileExists(sTempFile) then DeleteFile(sTempFile);  sOldMDB := sProvider + 'Data Source=' + DBFileName;
  sNewMDB := sProvider + 'Data Source=' + sTempFile;  try
    try
      IJetEng := CoJetEngine.Create;
      IJetEng.CompactDatabase(sOldMDB, sNewMDB);
    //  if FileExists(DBName) then DeleteFile(DBName);
      if not CopyFile(PChar(sTempFile), PChar(DBFileName), False) then
        sErr := 'Fail to overwrite the old database.';
    //  IJetEng := Nil;
    //  Result  := True;
    except
      on E: Exception do
        sErr := E.Message;
    end;
  finally
    IJetEng := Nil;
    if FileExists(sTempFile) then DeleteFile(sTempFile);
    if sErr <> '' then
    begin
      Result := 'Fail to compact database "' +DBFileName+ '".' +
                'Reason: ' + sErr;
     // MessageDlg(String(Result), mtError, [mbOK], 0);
    end
    else Result := 'Compact database "' +DBFileName+ '" successfully.';
 //   Result  := False;
  end;
end;procedure TdmDBConnection.DataModuleCreate(Sender: TObject);
const
  RegPath = '\Software\Tradelink\iTTS';
var
  Reg : TRegistry;
  sServerPath: String;
  sTemp: String;
begin  AccessMaster := TAccessApplication.Create(nil);  Reg := TRegistry.Create(KEY_READ);
  try
    Reg.RootKey := HKEY_LOCAL_MACHINE;
    if Reg.OpenKey(RegPath, False) then
    begin
      sServerPath := Reg.ReadString('ServerPath');
    //  LocalPath  := Reg.ReadString('LocalPath');
    //  Local_Version := Reg.ReadString('Version');
    end
    Else raise Exception.Create('Unable to open registry.');
    if (sServerPath = EmptyStr) or (Not DirectoryExists(sServerPath)) then
      raise Exception.Create('Unable to locate the server directory: ''' + sServerPath + '''');
  //  if (LocalPath = EmptyStr) or (Not DirectoryExists(LocalPath)) then
  //    raise Exception.Create('Unable to locate the local directory: ''' + LocalPath + '''');
    if sServerPath[Length(sServerPath)] <> '\' then sServerPath := sServerPath + '\';
    uSysCommon.ServerPath := sServerPath;
  //  if LocalPath[Length(LocalPath)] <> '\' then LocalPath := LocalPath + '\';
  finally
    Reg.CloseKey;
    Reg.Free;
  end;  BasePath := ExtractFilePath(Copy(sServerPath, 1, Length(sServerPath)-1));
  if Length(BasePath) > 0 then
    if BasePath[Length(BasePath)] <> '\' then BasePath := BasePath + '\';  sDataPath := BasePath + 'DATA';  sTemp := '';
  GetSysParam('POLICY', 'LOUTDB', sTemp);
  if sTemp <> '' then uSysSecCom.LOUTDB := sTemp
  else uSysSecCom.LOUTDB := BasePath + 'Sec\Out';  GetSysParam('POLICY', 'LINDB', sTemp);
  if sTemp <> '' then uSysSecCom.LINDB := sTemp
  else uSysSecCom.LINDB := BasePath + 'Sec\In';  ConnectDB('SysReg.mdb');
  
end;procedure TdmDBConnection.ConnectDB(MDBName: String);
const
  sProvider = 'Provider=Microsoft.Jet.OLEDB.4.0;';
begin
  with adocAccess do
  begin
    Connected:= False;
    ConnectionString := sProvider + 'Data Source=' + sDatapath +'\'+ MDBName;
    Connected:= True;
  end;
end;procedure TdmDBConnection.DataModuleDestroy(Sender: TObject);
begin
  adsGetSysParam.Active := False;
  adsCAInfo.Active := False;
  adocAccess.Connected := False;
  AccessMaster.Free;
end;procedure TdmDBConnection.SetSysParam(const pSection_ID, pIdent: string;
  sParam: string);
begin
  if not adocAccess.Connected then ConnectDB('SysReg.mdb');
  with adsGetSysParam do
  begin
    if Active then
      Close;
    Parameters.ParamByName('Section_ID').Value := pSection_ID;
    Parameters.ParamByName('Ident').Value := pIdent;
    Open;
    if RecordCount > 0 then
    begin
      First;
      Edit;
      FieldByName('Params').AsString := sParam;
      Post;
    end;
 //   else
 //     sParam := EmptyStr;
  //  ShowMessage(sParam);
    Close;
  end;
end;function TdmDBConnection.CompactMDB(sSourceDB: String): String;
var
  sErr, sTmpFile: String;begin
  sTmpFile := ExtractFileDir(Application.ExeName) + '\TmpAccessDB01.mdb';  if FileExists(sTmpFile) then DeleteFile(sTmpFile);
  Application.ProcessMessages;
  
  Result := 'Cannot compact the database. Reason: ';
  sErr := ''; // AccessMaster := TAccessApplication.Create(nil);
  try
    try
      AccessMaster.DBEngine.CompactDatabase(WideString(sSourceDB), WideString(sTmpFile),
                                            EmptyParam, EmptyParam, EmptyParam);
      Application.ProcessMessages;
      if not CopyFile(PChar(sTmpFile), PChar(sSourceDB), False) then
      begin
        sErr := 'Fail to overwrite the old database.';
        Abort;
      end
      else Result := 'Compact database "' +sSourceDB+ '" successfully.';
      Application.ProcessMessages;
    finally
    //  AccessMaster.Free;
      
    end;
  except
    on E: Exception do
    begin
    //  if AccessMaster <> nil then AccessMaster.Free;
      if sErr <> '' then
        Result := Result + sErr
      else
        Result := Result + E.Message;
    end;
  end;end;end.

Answer 9

to wlw88(飞扬):谢谢你！能给一个直接拷贝的例子么？简单点的为好。
to amei2000go(浪子):谢谢你！这两个函数直接害现了备份与恢复的功能了吗？
to Wally_wu(韦利):谢谢你！我调试时出现了很多问题，我现在头都晕了。 

Answer 10

CopyFile(Pchar('c:\from.txt'),Pchar('to.txt'),true);

Answer 11

CopyFile(Pchar('c:\from.txt'),Pchar('d:\to.txt'),true);

Answer 12

darkhorsedba(老牛) ：谢谢你！
 qwertyasd(昊) ：谢谢你！

Answer 13

谢谢各位的帮助！用简单的方法实现了（CopyFile），结贴！