Getting root parent

``` +--------+---------+-----------+ | id | title | parent_id | +--------+---------+-----------+ | 1 | Lvl-1 | null | +--------+---------+-----------+ | 2 | Lvl-2 | null | +--------+---------+-----------+ | 3 | Lvl-11 | 1 | +--------+---------+-----------+ | 4 | Lvl-12 | 1 | +--------+---------+-----------+ | 5 | Lvl-121 | 4 | +--------+---------+-----------+ ``` How do i actualy get root parent for each row For example, row with `id 5` have parent with `id 4` and `id 4` have parent with `id 1`, so root id for `id 5` is `id 1` I dont have any idea on how to do it and is there a way to solve this by using only 1 query