Vous devriez mieux garder parent_id
mais pas le nom du parent.
Voici une solution rapide pour commander votre table http://sqlfiddle.com/#!9/2a1fb /3
SELECT *
FROM table1
ORDER BY
CASE WHEN parent_id IS NULL THEN CAST(ID AS CHAR)
ELSE CONCAT(CAST(parent_id AS CHAR),'-', CAST(ID AS CHAR)) END
MODIFICATION 1 Variante #2 :-) http://sqlfiddle.com/#!9/76dcb/23
SELECT t1.*
FROM table1 t1
LEFT JOIN table1 t2
ON t2.ID = t1.parent_id
ORDER BY
CASE WHEN t2.ord_idx IS NULL THEN CAST(t1.ord_idx AS CHAR)
ELSE CONCAT(CAST(t2.ord_idx AS CHAR),'-',CAST(t1.ord_idx AS CHAR)) END
MODIFICATION 2 pour voir comment cette commande fonctionne, vous pouvez simplement ajouter ce champ pour sélectionner une partie comme :
SELECT t1.*, CASE WHEN t2.ord_idx IS NULL THEN CAST(t1.ord_idx AS CHAR)
ELSE CONCAT(CAST(t2.ord_idx AS CHAR),'-',CAST(t1.ord_idx AS CHAR)) END as my_order
FROM table1 t1
LEFT JOIN table1 t2
ON t2.ID = t1.parent_id
ORDER BY
CASE WHEN t2.ord_idx IS NULL THEN CAST(t1.ord_idx AS CHAR)
ELSE CONCAT(CAST(t2.ord_idx AS CHAR),'-',CAST(t1.ord_idx AS CHAR)) END