Читаем файл Access используя ADO

// Читаем файл (любой версии) 
// Проверяем что это ACCESS MDB 
// Нужны компаненты: 
// TADOtable,TDataSource,TOpenDialog,TDBGrid,TBitBtn. 
unit uMain; 

interface 

uses 
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, 
Db, DBTables, ADODB, Grids, DBGrids, ExtCtrls, DBCtrls, StdCtrls, Buttons; 

type 
 TfrmMain = class(TForm) 
 DSUsers: TDataSource; 
 DBGridUsers: TDBGrid; 
 BitBtn1: TBitBtn; 
 OpenDialog1: TOpenDialog; 
 TUsers: TADOTable; 
 procedure FormCreate(Sender: TObject); 
 procedure ValidateAccessDB; 
 function CheckIfAccessDB(lDBPathName: string): boolean; 
 private 
 { Private declarations } 
 public 
 { Public declarations } 
 end; 

var 
 frmMain: TfrmMain; 
const 
 DBNAME = 'ADODemo.MDB'; 
 DBPASSWORD = '123'; // Access DB Password Protected 

implementation 

{$R *.DFM} 

procedure TfrmMain.FormCreate(Sender: TObject); 
begin 
 validateAccessDB; 
end; 

procedure TfrmMain.ValidateAccessDB; 
var 
 lDBpathName : String; 
 lDBcheck : boolean; 
begin 
 if FileExists(ExtractFileDir(Application.ExeName) + '\' + DBNAME) then 
 lDBPathName := ExtractFileDir(Application.ExeName) + '\' + DBNAME 
 else if OpenDialog1.Execute then 
 // Set the OpenDialog Filter for ADOdemo.mdb only 
                                lDBPathName := OpenDialog1.FileName; 

 lDBCheck := False; 
 if Trim(lDBPathName) <> '' then 
 lDBCheck := CheckIfAccessDB(lDBPathName); 

 if lDBCheck = True then 
 begin 
 // ADO Connection String to the MS-ACCESS DB 
                                TUsers.ConnectionString := 
 'Provider=Microsoft.Jet.OLEDB.4.0;' + 
 'Data Source=' + lDBPathName + ';' + 
 'Persist Security Info=False;' + 
 'Jet OLEDB:Database Password=' + DBPASSWORD; 
 TUsers.TableName := 'Users'; 
 TUsers.Active := True; 
 end 
 else 
 frmMain.Free; 
end; 

// Check if it is a valid ACCESS DB File Before opening it. 

function TfrmMain.CheckIfAccessDB(lDBPathName: string): Boolean; 
var 
 UnTypedFile: file of byte; 
 Buffer: array[0..19] of byte; 
 NumRecsRead: Integer; 
 i: Integer; 
 MyString: string; 
begin 
 AssignFile(UnTypedFile, lDBPathName); 
 reset(UnTypedFile); 
 BlockRead(UnTypedFile, Buffer, High(Buffer), NumRecsRead); 
 CloseFile(UnTypedFile); 
 for i := 1 to High(Buffer) do 
 MyString := MyString + Trim(Chr(Ord(Buffer[i]))); 
 Result := False; 
 if Mystring = 'StandardJetDB' then 
 Result := True; 
 if Result = False then 
 MessageDlg('Invalid Access Database', mtInformation, [mbOK], 0); 
end; 
end.