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Saturday, 10 September 2011

Login Form Delphi by Connecting to Ms Access Database.

this the step by step  to making application :

Login Form Delphi by Connecting Ms Access Database.

In making/ building application in Delphi, login Form is an important to protect application so that cannot be open by irresponsible person.
This login Form is connected with database so that able to keep a lot of username data and password.
Before make the application, please create a database as the picture below:

Picture :Login  form Delphi database Microsoft Access

Save the database in the folder which use to save the application


Next step is create the application

Enter the component and the source code as follows.


No
Component Name Properties Value
1 Label1 Caption Username
2 Label2 Caption Password
3 Edit1 Text -
4 Edit2 Text -
5 Button1 Caption Login
6 Adoconnection1 - -
7 AdoQuery1 Connection ADOConnection1


Arrange the component as the picture below:


Figure. Login Form Delphi design form




 Create new form



Form properties can be check in the table below
No Component Name Properties Value
1 Form1 Caption Success Login
Name Hasil_Login


Type the source code Below

No
Component Name Event Source code
1 Form1 OnCreate var
s : Char;
dbaddress : WideString;
begin
s := '*';
edusername.Text := '';
edpassword.PasswordChar := s;
edpassword.Text := '';
  dbaddress := ExtractFilePath(Application.ExeName) + 'data.mdb';
with ADOConnection1 do begin
Connected := False;
LoginPrompt := False;
Mode := cmShareDenyNone;
ConnectionString := 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=' +
alamatdb + ';Persist Security Info=False';
end;
  ADOConnection1.Connected := True;
end;
2 Button1 OnClick   with ADOQuery1 do begin
    Close;
    SQL.Clear; // bersihkan perintah sql jika ada
    SQL.Add('select * from login where username='+
    QuotedStr(edusername.Text));
    Open;
  end; // end with

  // jika tidak ditemukan data yang dicari maka
  // tampilkan pesan

  if ADOQuery1.RecordCount = 0 then
      Application.MessageBox('wrong username!!!!!!', 'Information',
      MB_OK or MB_ICONINFORMATION)
  else begin
    if ADOQuery1.FieldByName('password').AsString <> edpassword.Text
      then Application.MessageBox('Be sure user name and password is correct', 'Error',
      MB_OK or MB_ICONERROR)
  else begin
    Hide;
    Hasil_Login.Show;
    end
  end;

This is the Login Form Application:








When wrong username



Picture :Login  form Delphi wrong username


When Wrong Password



Picture :Login  form Delphi wrong Password

 All the source code is appear below:


unit ULogin;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, DB, ADODB, ExtCtrls;
type
TFrmLogin = class(TForm)
Label1: TLabel;
edusername: TEdit;
Label2: TLabel;
edpassword: TEdit;
Button1: TButton;
ADOQuery1: TADOQuery;
ADOConnection1: TADOConnection;
procedure Button1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
FrmLogin: TFrmLogin;
implementation
uses
XPMan, UHasilLogin, Unit2;
{$R *.dfm}
procedure TFrmLogin.FormCreate(Sender: TObject);
var
s : Char;
dbaddress : WideString;
begin
s := '*';
edusername.Text := '';
edpassword.PasswordChar := s;
edpassword.Text := '';
  dbaddress := ExtractFilePath(Application.ExeName) + 'data.mdb';
with ADOConnection1 do begin
Connected := False;
LoginPrompt := False;
Mode := cmShareDenyNone;
ConnectionString := 'Provider=Microsoft.Jet.OLEDB.4.0;Data Source=' +
alamatdb + ';Persist Security Info=False';
end;
  ADOConnection1.Connected := True;
end;
procedure TFrmLogin.Button1Click(Sender: TObject);
begin
with ADOQuery1 do begin
Close;
SQL.Clear;    SQL.Add('select * from login where username='+
QuotedStr(edusername.Text));
Open;
end;
if ADOQuery1.RecordCount = 0 then
Application.MessageBox('wrong username!!!', 'Information',
MB_OK or MB_ICONINFORMATION)
else begin
if ADOQuery1.FieldByName('password').AsString <> edpassword.Text
then Application.MessageBox('Be sure user name and password is correct', 'Error',
MB_OK or MB_ICONERROR)
else begin
Hide;
Hasil_Login.Show;
end
end;
end;
end.


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Related : Login Form Delphi by Connecting to Ms Access Database.