SQL 重复问题 SQL SERVER 2000

Question

我有两个表：Product 和 ProductRateDetail。父表是产品。我在产品表中有重复的记录，这些记录需要是唯一的。 ProductRateDetail 表中有对应于产品表中重复记录的条目。

不知何故，我需要更新 ProductRateDetail 表以匹配 Product 表中的原始（旧）ID，然后从 product 表中删除重复项。我会手动执行此操作，但有 100 条记录。即类似

UPDATE tbl_productRateDetail SET productID = (originalID from tbl_product)

然后类似

DELETE from tbl_product WHERE duplicate ID

并且只删除最近添加的ID数据

示例：（抱歉无法解决这个格式化问题）

tbl_Product

select * from dbo.Product where ProductCode = '10003'

ProductID    ProductTypeID    ProductDescription       ProductCode     ProductSize
365          1             BEND DOUBLE FLANGED      10003           80mmX90deg
1354            1             BEND DOUBLE FLANGED      10003           80mmX90deg

tbl_ProductRateDetail

SELECT * FROM [MSTS2].[dbo].[ProductRateDetail] WHERE ProductID in (365,1354)

ProductRateDetailID ProductRateID   ProductID   UnitRate
365                    1               365            16.87
1032                   5               365            16.87
2187                   10              365            16.87
2689                   11              365            16.87
3191                   12              365            16.87
7354                   21              1354           21.30
7917                   22              1354           21.30
8480                   23              1354           21.30
9328                   25              1354           21.30
9890                   26              1354           21.30
10452                  27              1354           21.30

Answer 1

未经测试，所以语法可能有一些错误。

首先，从分组的产品中取出最小的产品id，并更新ProductRateDetail中的记录

UPDATE prd1
SET prd1.ProductID = p2.ProductID
FROM ProductRateDetail prd1
INNER JOIN Product p1 ON
p1.ProductID = prd1.ProductID
INNER JOIN
(
SELECT MIN(ProductID) AS ProductID, ProductTypeID, ProductDescription, ProductCode, ProductSize
FROM Product
GROUP BY ProductTypeID, ProductDescription, ProductCode, ProductSize
) p2 ON
p1.ProductTypeID = p2.ProductTypeID AND
p1.ProductDescription = p2.ProductDescription AND
p1.ProductCode = p2.ProductCode AND
p1.ProductSize = p2.ProductSize

然后，删除不是“选定”id的分组产品

DELETE p1
FROM Product p1
INNER JOIN
(
SELECT MIN(ProductID) AS ProductID, ProductTypeID, ProductDescription, ProductCode, ProductSize
FROM Product
GROUP BY ProductTypeID, ProductDescription, ProductCode, ProductSize
) p2 ON
p1.ProductTypeID = p2.ProductTypeID AND
p1.ProductDescription = p2.ProductDescription AND
p1.ProductCode = p2.ProductCode AND
p1.ProductSize = p2.ProductSize AND
p1.ProductID != p2.ProductID

Answer 2

这样的事情应该可以工作：

1) 更新引用重复的产品详细信息

UPDATE tbl_productRateDetail d
   SET productID = (SELECT MIN(p0.productID)
                      FROM tbl_product p0
                      JOIN tbl_product p1 
                            ON p1.ProductTypeID = p0.ProductTypeID
                           AND p1.ProductDescription = p0.ProductDescription
                           AND p1.ProductCode = p0.ProductCode
                           AND p1.ProductSize = p0.ProductSize
                     WHERE p1.productID = d.productId)
 WHERE productID IN (SELECT productID
                       FROM tbl_product
                      WHERE (ProductTypeID, 
                             ProductDescription, 
                             ProductCode, 
                             ProductSize) IN
                            (SELECT ProductTypeID, 
                                    ProductDescription, 
                                    ProductCode,
                                    ProductSize
                               FROM tbl_product
                              GROUP BY ProductTypeID, 
                                       ProductDescription, 
                                       ProductCode, 
                                       ProductSize
                             HAVING COUNT(*) > 1));

2) 删除重复项

DELETE FROM tbl_product p0
 WHERE productID <> (SELECT MIN(productID)
                       FROM tbl_product p1
                      WHERE p1.ProductTypeID = p0.ProductTypeID
                        AND p1.ProductDescription = p0.ProductDescription
                        AND p1.ProductCode = p0.ProductCode
                        AND p1.ProductSize = p0.ProductSize);