Question

我正在尝试查找表中的所有重复项并更改其中一个值。现在我使用：

SELECT Amount
FROM Bids
GROUP BY Amount, AuctionID
HAVING ( COUNT(Amount) > 1 ) AND  (AuctionID=1)

仅返回

的问题

Amount
23.6500
41.8800
42.3500

而不是

Amount
23.6500
23.6500
41.8800
41.8800
42.3500
42.3500

所以我无法更新所有行。

我怎样才能按照我展示的方式获得它？

谢谢，丹

Answer 1

将其包装在IN查询中：

SELECT Amount
FROM Bids
WHERE Amount IN (
  SELECT Amount
  FROM Bids
  GROUP BY Amount, AuctionID
  HAVING ( COUNT(Amount) > 1 ) AND  (AuctionID=1)
)

更新：添加了UPDATE语句

UPDATE Bids
SET Burned = 1
WHERE Amount IN (
  SELECT Amount
  FROM Bids
  GROUP BY Amount, AuctionID
  HAVING ( COUNT(Amount) > 1 ) AND  (AuctionID=1)
)

Answer 2

假设您在出价表中有Id：

 SELECT Amount
 FROM Bids b1
 WHERE AcutionId = 1
 AND EXISTS (Select 1 from Bids b2 
             WHERE b2.AuctionID = b1.AuctionId 
             AND b1.Amount = b2.Amount
             AND b1.Id <> b2.Id)

Answer 3

我很想知道为什么你的原始选择不满足你的要求。如果对于一组重复项中的每个成员，您只选择其中一个，那么您需要更新一个。将AuctionId添加到Frank Schmitt提供的选择中以查看区分这些行的信息应该是有用的。

在SQL中查找重复项并更新它们？

3 个答案: