MySQL 8.0

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CREATE TABLE categories (
  id varchar(11) NOT NULL,
  parentId varchar(11) NULL,
  name varchar(100) NOT NULL,
  path varchar(100) NOT NULL,
  timestamp int(100) NOT NULL
)
INSERT INTO `categories` (`id`, `parentId`, `name`, `path`, timestamp) VALUES
('A1', null, 'Cat 1', 'Cat 1', 1),
('A2', 'A1', 'Cat 2', 'Cat 1 > Cat 2', 2),
('A3', 'A2', 'Cat 3', 'Cat 1 > Cat 2 > Cat 3', 3),
('A4', null, 'Cat A', 'Cat A', 4),
('A5', 'A4', 'Cat B', 'Cat A > Cat B', 5);

Records: 5  Duplicates: 0  Warnings: 0


with recursive cte (id, name, parentId) AS (
    select
        id,
        name,
        parentId
    from
        categories
    where
        parentId = 'A1'
    union
    all
    select
        c.id,
        c.name,
        c.parentId
    from
        categories c
        inner join cte on c.parentId = cte.id
)
select
    *
from
    cte;


id
name
parentId


A2
Cat 2
A1

A3
Cat 3
A2