procedure TForm1.Button1Click(Sender: TObject);
var
  Info: TStrings;
begin
  Info := TStringList.Create;
  try
    FDConnection.GetInfoReport(Info);
    ShowMessage(Info.Text);
  finally
    Info.Free;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage(FDConnection1.ResultConnectionDef.BuildString);
end;

// Способ первый
procedure TForm1.Button1Click(Sender: TObject);
begin
  FDConnection1.Open('Password=MyPass;Database=MyDB;User_Name=MyUser;DriverID=Ora');
end;

// Способ второй
procedure TForm1.Button1Click(Sender: TObject);
begin
  FDConnection1.ConnectionString := 'Password=MyPass;Database=MyDB;User_Name=MyUser;DriverID=Ora';
  FDConnection1.Open;
end;

// Способ третий
procedure TForm1.Button1Click(Sender: TObject);
begin
  FDConnection1.Params.Add('Password=MyPass');
  FDConnection1.Params.Add('Database=MyDB');
  FDConnection1.Params.Add('User_Name=MyUser');
  FDConnection1.Params.Add('DriverID=Ora');
  FDConnection1.Open;
end;

// Способ четвертый
procedure TForm1.Button1Click(Sender: TObject);
var
  oParams: TStrings;
begin
  oParams := TStringList.Create;
  try
    oParams.Add('Password=MyPass');
    oParams.Add('Database=MyDB');
    oParams.Add('User_Name=MyUser');
    FDManager.AddConnectionDef('ORA_Connection', 'Ora', oParams);
    FDConnection1.ConnectionDefName := 'ORA_Connection';
    FDConnection1.Open;
  finally
    oParams.Free;
  end;
end;

// Способ первый
uses
  FireDAC.VCLUI.ConnEdit;

procedure TForm1.Button1Click(Sender: TObject);
var
  sConnStr: string;
begin
  sConnStr := 'Password=MyPass;Database=MyDB;User_Name=MyUser;DriverID=Ora';
  if TfrmFDGUIxFormsConnEdit.Execute(sConnStr, '') then
  begin
    FDConnection1.ResultConnectionDef.ParseString(sConnStr);
    FDConnection1.Open;
  end;
end;

// Способ второй
uses
  FireDAC.VCLUI.ConnEdit;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if TfrmFDGUIxFormsConnEdit.Execute(FDConnection1, '') then
    FDConnection1.Connected := True;
end;