Sletning af hierarkiske data i SQL-tabel

På SQL Server:Brug en rekursiv forespørgsel. Givet CREATE TABLE tmp(Id int, Parent int), brug

WITH x(Id) AS (
    SELECT @Id
    UNION ALL
    SELECT tmp.Id
      FROM tmp
      JOIN x ON tmp.Parent = x.Id
)
DELETE tmp
  FROM x
  JOIN tmp ON tmp.Id = x.Id