Question

I have this table.

I want to select cat id = 4 and every other row its cat parent id equals to.
e.g. if I want all categories from cat id 4, it should result to cat ids 4 (itself), 2 and 1

+-------------------------------+
| id   |  catname  | catparentid |
+-------------------------------+
|1     |  home     |    0        |
|2     |  products |    1        |
|3     |  men      |    2        |
|4     |  women    |    2        |
|5     |  shirts   |    3        |
|6     |  outdoor  |    0        |
+-------------------------------+

I tried:

SELECT * FROM categories c
where c.id = 4 
c.catparentid IN (SELECT id FROM categories)

But it brings up all. Do I need to do a union?

Answer 1

SELECT *
FROM categories c
INNER JOIN (SELECT catparentid FROM categories where id = 4) a
ON c.catparentid = a.catparentid