在SQL中計算股票突變

Question

我想計算出庫=每天離開倉庫的產品數量。 如果我運行這些查詢，我可以看到sql正在以某種方式計數數量，但我不明白為什么。 有人可以看到問題嗎？ 如何避免這種情況？

SELECT readYesterday.ArticleCode,
       MAX(readToday.ArticleCode) AS ArticleCodeToday,
       readYesterday.ReportDate,
       SUM(ISNULL(readToday.TotalStock, 0)) AS TotalStockToday,
       SUM(readYesterday.TotalStock) AS TotalStockYesterday,
       SUM(readYesterday.TotalStock - ISNULL(readToday.TotalStock, 0)) AS Outbound
FROM ArticleReads readYesterday
LEFT JOIN ArticleReads readToday ON readToday.ArticleCode = readYesterday.ArticleCode
AND readToday.InboundDossier = readYesterday.InboundDossier
AND readToday.ReportDate = DATEADD(DAY, 1, readYesterday.ReportDate)
WHERE readYesterday.ArticleCode ='ART01234'
  AND readToday.ReportDate <> Convert(date, getdate())
  AND readYesterday.ReportDate = '2018-04-26'
GROUP BY readYesterday.ArticleCode,
         readYesterday.ReportDate
ORDER BY ReportDate ASC

SELECT *
FROM ArticleReads readYesterday
WHERE readYesterday.ArticleCode = 'ART01234'
  AND readYesterday.ReportDate = '2018-04-26'

SELECT *
FROM ArticleReads readYesterday WHERE readYesterday.ArticleCode = 'ART01234'
AND readYesterday.ReportDate = '2018-04-27'

在這里您可以看到結果

Answer 1

在連接昨天和今天的表時，必須確保您已連接主鍵。 在您的情況下，您正在使用文章代碼，inbounddossieur和reportdate + 1； 但是，由於每行有2行，沒有任何區別，因此聯接將返回4行！ 您需要添加一個連接條件，該條件唯一地指定每一行-也許是位置碼？

and readToday.LocationCode=readYesterday.LocationCode