purge loop, why?

sqlpurgeloop.sql

SET @rows = 5 --default

IF @purgeDate is NULL SET @purgeDate=getdate()

-- Only execute if there is work to do and continue 
-- until all records with a PurgeDate <= now are deleted

WHILE EXISTS(SELECT * FROM WorkItemStatus WHERE PurgeDate <= @purgeDate) 
BEGIN
	-- NB:  the FK in WorkStatus has ON DELETE CASCADE,
	-- so it will delete corresponding rows automatically

	DELETE TOP (@rows) 
	FROM WorkItemStatus
	WHERE PurgeDate <= @purgeDate

END -- WHILE EXISTS(