Remove empty meta values from meta query

Hello all

I am trying to query posts using a bunch of user selectable fields for the values of meta mquery. However my issuesis, if a user leaves a field blank, the query still includes that field. Is there any way I can get the query to simply ignore that field if its empty?
Thanks

Heres what I have so far.

$operatorname = ($_POST['operatorname']);
$apartmentname = ($_POST['apartmentname']);
$location = ($_POST['location']);
$startdate = ($_POST['startdate']);
$enddate = ($_POST['enddate']);
$andor = ($_POST['andor']);

$args = array(
			'post_type' => 'bookings',
			'meta_query' => array(
				'relation' => $andorvalue,
					array(
						'key' => 'operatorname',
						'value' => $operatorname,
						'compare' => '=',
					),
					array(
						'key' => 'apartmentname',
						'value' => $apartmentname,
						'compare' => '=',

					),
			),
			'date_query' => array(
			        array(
			            'after' => $startdate,
			            'before' => $enddate,
			        ),
			),
		);