ngOnInit() {
this.hero$ = this.route.paramMap.pipe(
switchMap((params: ParamMap) =>
this.service.getHero(params.get('id')))
);
}
SELECT t1.id, Автомобили.name, t1.category_id from
(
SELECT MAX(id) as id, category_id FROM Автомобили WHERE category_id IN
(SELECT id FROM Категории WHERE parent_id = 0)
GROUP BY category_id
) t1 left join Автомобили on Автомобили.id = t1.id