Unit CompactMDB;

Interface
Uses
   Windows, SysUtils, Math, ComObj, shellapi, Shlobj;
Function CompactDatabase(Const AFileName, APassWord: String): Boolean;
Implementation

Function CompactDatabase(Const AFileName, APassWord: String): Boolean;
Const
   SConnectionString = 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=%s;'
      + 'Jet OLEDB:Database Password=%s;';
Var
   SPath            : String;
   SFile            : Array[0..254] Of char;
   STempFileName    : String;
   JE               : OleVariant;

   Function GetTempDir: String;
   Var
      Buffer        : Array[0..MAX_PATH] Of char;
   Begin
      ZeroMemory(@Buffer, MAX_PATH);
      GetTempPath(MAX_PATH, Buffer);
      result := IncludeTrailingBackslash(StrPas(Buffer));
   End;

Begin
   result := false;
   SPath := GetTempDir;                 //取得Windows的Temp路徑
   GetTempFileName(pchar(SPath), '~ACP', 0, SFile);
          //取得Temp文件名,Windows將自動建立0字節文件
   STempFileName := SFile;              //PChar->String
   If Not DeleteFile(STempFileName) Then Exit; //刪除Windows建立的0字節文件
   Try
      JE := CreateOleObject('JRO.JetEngine');
               //建立OLE對象,函數結束OLE對象超過作用域自動釋放
      OleCheck(JE.CompactDatabase(Format(SConnectionString, [AFileName,
         APassWord]),
            Format(SConnectionString, [STempFileName, APassWord])));
                         //壓縮數據庫
        //復制并覆蓋源數據庫文件,如果復制失敗則函數返回假,壓縮成功但沒有到函數的功能
      result := CopyFile(pchar(STempFileName), pchar(AFileName), false);
      DeleteFile(STempFileName);        //刪除臨時文件
   Except
        //壓縮失敗
   End;
End;

End.