sql自然周統計

-- 最近2個自然周統計：
SELECT count(CASE WHEN (int(datediff(scheduled_date,'2001-01-01')/7) 
    IN (int(datediff(CURRENT_DATE,'2001-01-01')/7)-2,int(datediff(CURRENT_DATE,'2001-01-01')/7)-1)
	AND class_status='FINISHED' AND finish_type='AS_SCHEDULED') THEN scheduled_date END) AS last_2week__cnt
FROM xxx.xxx