set term ^ ;

create or alter procedure test_proc
returns (res varchar(30))
as
begin
  execute statement 'select ''1'' from rdb$database'
  on external 'TESTDB2'
  as user 'TUSER' password 'test'
  into :res;
  suspend;
end^

set term ; ^

procedure TForm1.Button1Click(Sender: TObject);
begin
  FDPhysFBDriverLink1.Embedded := True;
  FDPhysFBDriverLink1.VendorLib := 'fbembed.dll';
  FDPhysFBDriverLink1.DriverID := 'FB';
  FDConnection1.DriverName := 'FB';
  FDConnection1.Params.Database := 'TESTDB1';
  FDConnection1.Params.UserName := 'TUSER';
  FDConnection1.Params.Password := 'test';
  FDConnection1.LoginPrompt := False;
  FDQuery1.Connection := FDConnection1;
  FDQuery2.Connection := FDConnection1;
  FDConnection1.Open;

  FDQuery1.SQL.SetText('select * from test_proc');
  FDQuery1.Open;
  ShowMessage(FDQuery1.Fields[0].AsString);
  FDQuery1.Close;
  FDConnection1.Close;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  i: integer;
begin
  FDPhysFBDriverLink1.Embedded := True;
  FDPhysFBDriverLink1.VendorLib := 'fbembed.dll';
  FDPhysFBDriverLink1.DriverID := 'FB';
  FDConnection1.DriverName := 'FB';
  FDConnection1.Params.Database := 'TESTDB1';
  FDConnection1.Params.UserName := 'TUSER';
  FDConnection1.Params.Password := 'test';
  FDConnection1.LoginPrompt := False;
  FDQuery1.Connection := FDConnection1;
  FDQuery2.Connection := FDConnection1;
  FDConnection1.Open;

  FDQuery1.SQL.SetText('select * from test_proc');
  FDQuery1.Open;
  FDQuery1.Close;

  try
    i := 0;
    repeat
      FDQuery2.SQL.SetText('select * from rdb$database');
      FDQuery2.Open;
      FDQuery2.Close;
      Sleep(1000);
      inc(i);
    until False;
  except
    on E: Exception do
      ShowMessage('i = ' + i.ToString + ' E.Message = ' + E.Message);
  end;
  FDConnection1.Close;
end;