Читаем файл Access используя ADO

Добавил на всякий случай, чтобы не забыть…. Немного подправил! =)

// Читаем файл (любой версии)
// Проверяем что это ACCESS MDB
// Нужны компаненты:
// TADOtable,TDataSource,TOpenDialog,TDBGrid,TBitBtn.
// Исправил: TUsers на ADOTable1 - Не всем просто сразу понятно, что такое TUsers
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
ADOTable1.ConnectionString :=
'Provider=Microsoft.Jet.OLEDB.4.0;' +
'Data Source=' + lDBPathName + ';' +
'Persist Security Info=False;' +
'Jet OLEDB:Database Password=' + DBPASSWORD;
ADOTable1.TableName := 'Users';
ADOTable1.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.

// Читаем файл (любой версии)

// Проверяем что это ACCESS MDB

// Нужны компаненты:

// TADOtable,TDataSource,TOpenDialog,TDBGrid,TBitBtn.

// Исправил: TUsers на ADOTable1 - Не всем просто сразу понятно, что такое TUsers

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

ADOTable1.ConnectionString :=

'Provider=Microsoft.Jet.OLEDB.4.0;' +

'Data Source=' + lDBPathName + ';' +

'Persist Security Info=False;' +

'Jet OLEDB:Database Password=' + DBPASSWORD;

ADOTable1.TableName := 'Users';

ADOTable1.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.

Код рабочий, проверял на Delphi 7

Источник: http://www.delphisources.ru/pages/faq/base/read_access_with_ado.html

Daniil V. Savenkov

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Читаем файл Access используя ADO