public function find_all_by_section( $section_id ) {
		global $wpdb;
		$post_types_string = models\Lesson::lesson_cpts();
		$post_types_string = implode( "','", $post_types_string );

		$query = $wpdb->prepare(
			"SELECT ID, post_type FROM {$wpdb->posts} AS p
	        JOIN {$wpdb->postmeta} AS pm
	          ON p.ID = pm.post_id
	         AND pm.meta_key = %s
	         AND pm.meta_value = %s
	        JOIN {$wpdb->postmeta} AS pm_order
	          ON p.ID = pm_order.post_id
	         AND pm_order.meta_key = %s
	       WHERE p.post_type in ( %s ) AND p.post_status <> 'trash'
	       ORDER BY pm_order.meta_value * 1",
			models\Lesson::$section_id_str,
			$section_id,
			models\Lesson::$lesson_order_str,
			stripcslashes( $post_types_string )
		);

		$db_lessons = $wpdb->get_results( stripcslashes( $query ) ); //phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
		$lessons    = array();

		foreach ( $db_lessons as $lesson ) {
			if ( models\Quiz::$cpt === $lesson->post_type ) {
				$lessons[] = $lesson->ID;
			} else {
				$lessons[] = $lesson->ID;
			}
		}

		return $lessons;
	}