Accidentally deleted my Ubuntu calendar - how do I get it back?

Question

Calendar

Accidentally deleted the Ubuntu calendar - how to install it back?
(I can’t see the uninstall history - I deleted many programs in a row)

Answer 1

Issue resolved:
sudo apt-get install indicator-datetime

Answer 2

The prepared statements mechanism was originally conceived to substitute only data into the request. The request structure cannot be changed.

Answer 3

$num = '1';
$fields = 'title';

$stm = $pdo->prepare('SELECT * FROM products WHERE id=?');
$stm->execute([$num]);
$data = $stm->fetch();

var_dump($data[$fields]);