從另一列中刪除不在最小和最大日期之間的行

Question

我想從表中另一個（可爲空）的列中刪除不在MIN和MAX之間的記錄。

這裏是SQL小提琴建設模式和樣本數據：

http://www.sqlfiddle.com/#!3/14686

我一直在嘗試這樣的事情（這ofcourse不工作）：

DELETE FROM MeterReadings 
WHERE ScheduledReadingDate NOT BETWEEN MIN(ActualReadingDate) and MAX(ActualReadingDate) 
GROUP BY MeterId 

怎麼辦我做到了？

Answer 1

可以先選中最小和最大的日期，然後做比較：

with cte as(select *, 
        min(ActualReadingDate) over(partition by meterid) as MinDate, 
        max(ActualReadingDate) over(partition by meterid) as MaxDate    
      from meterreadings) 
delete from cte 
where ScheduledReadingDate not between MinDate and MaxDate 

Answer 2

試試這個

;WITH cte 
    AS (SELECT Min(ActualReadingDate) m_ActualReadingDate, 
       Max(ActualReadingDate) ma_ActualReadingDate, 
       MeterId 
     FROM MeterReadings 
     GROUP BY MeterId) 
DELETE M 
FROM MeterReadings M 
WHERE EXISTS (SELECT 1 
       FROM cte c 
       WHERE c.MeterId = m.MeterId 
         AND m.ScheduledReadingDate < m_ActualReadingDate 
         AND m.ScheduledReadingDate > ma_ActualReadingDate)