SQL select for a specific node all subnodes

Question

I'm using mySQL on phpMyAdmin, my table is

| code | name | parent |
|------|------|--------|
|  10  |node10|   5    |
|  5   |node05|   2    |

where 5 is the parent of 10 (which is also a node), I need to select for a specific node A all childs and subchilds until the last leaf, I tried to do that but I've got also 2 levels of subchilds (for example for node 2 I've got 5 and 10)

SELECT * 
FROM `composant` 
WHERE parent IN( 
    SELECT code 
    FROM `composant` 
    WHERE parent=2 OR code=2
)

so how can we get loop to get all the subnodes ?