categories_map_with_parent_id_recursive.sql

SELECT 
	t1.id as level_1, 
	t4.level_2, 
	t4.level_3 
FROM 
	`categories` t1 
	LEFT JOIN (
		SELECT 
			t2.id as level_2, 
			t2.parent_id as level_2_parent_id, 
			t3.id as level_3 
		FROM 
			`categories` t2 
			LEFT JOIN `categories` t3 ON t2.id = t3.parent_id
	) as t4 ON t1.id = t4.level_2_parent_id