BEGIN TRAN
UPDATE sp
SET ParentID = 1
FROM SectionParents AS sp WITH (HOLDLOCK TABLOCKX)
WHERE 1 = 0

TRUNCATE TABLE SectionParents

;WITH cte AS (
	SELECT
		ID AS ParentID, ID
	FROM
		dbo.Section

	UNION ALL
                             
	SELECT
		c.ParentID, s.ID
	FROM
		cte AS c
		INNER JOIN dbo.Section AS s ON s.spRef = c.ID
	WHERE
		s.ID <> s.spRef)

INSERT INTO SectionParents(ParentID, ID)
select *
from cte

COMMIT