wp_query_employee

// WP_Query arguments
$args = array(
	'post_type'              => array( 'employee' ),
	'post_status'            => array( 'publish' ),
	'meta_query'             => array(
		'relation' => 'OR',
		array(
			'key'     => 'emp_id',
		),
	),
);

// The Query
$query = new WP_Query( $args );