Question

我在sql server上有一组数据，如：

ID ID_Invoice Article Quantity Status
1  10         carrot  10       null
2  10         carrot  5        C
3  10         onion   8        null
4  10         onion   4        C
5  11         tomato  20       null
6  11         tomato  18       C
7  11         onion   2        null
8  11         onion   1        C

这意味着客户订购了10个胡萝卜和8个洋葱（在一张发票上）但实际上只收到了5个胡萝卜和4个洋葱。如果status为null则为原始数量，如果status为C则为校正数量

我需要生成一个像

这样的表格

ID ID_Invoice Article Quantity 
1  10         carrot  -5       
2  10         onion   -4
3  11         tomato  -2
4  11         onion   -1

显示每张发票上的订购数量和实际数量之间的差异。我不知道如何开始。任何帮助深深赞赏:)

Answer 1

带有简单CASE表达式的选项，没有过多的JOIN

SELECT ID_Invoice, Article, 
       SUM(CASE WHEN Status IS NULL 
  THEN -1 * Quantity ELSE Quantity END) AS Quantity
FROM dbo.test38
GROUP BY ID_Invoice, Article

结果：

ID_Invoice Article Quantity 
10  carrot  -5
10  onion   -4
11  onion   -1
11  tomato  -2

SQLFiddle上的演示

Answer 2

您没有指定，您正在使用哪个RDBMS，但我的答案是符合ANSI-SQL标准:)与每个有效的RDBMS一起使用。

SELECT
yt1.ID_Invoice, 
yt1.Article,
yt2.Quantity - yt1.Quantity AS Quantity
FROM
yourTable yt1
INNER JOIN yourTable yt2 ON yt1.ID_Invoice = yt2.ID_Invoice 
                            AND yt1.Article = yt2.Article 
                            AND yt2.Status = 'C'
WHERE
yt1.Status IS NULL

这个答案是假设的，总是一个状态为NULL的记录和状态为“C”的相应行。如果不是这种情况，你必须像这样调整它：

SELECT
yt1.ID_Invoice, 
yt1.Article,
CASE WHEN yt2.Quantity IS NULL THEN yt1.Quantity ELSE yt2.Quantity - yt1.Quantity END AS Quantity
FROM
yourTable yt1
LEFT JOIN yourTable yt2 ON yt1.ID_Invoice = yt2.ID_Invoice 
                            AND yt1.Article = yt2.Article 
                            AND yt2.Status = 'C'
WHERE
yt1.Status IS NULL

Answer 3

资源密集程度最低：

SELECT id_invoice
, article
, org_quantity
, new_quantity
, new_quantity - org_quantity diff
FROM (SELECT id_invoice
      , article
      , max(CASE WHEN status IS NULL THEN quantity else null END) org_quantity
      , max(CASE WHEN status = 'C' THEN quantity else null END) new_quantity
      FROM   orders
      GROUP BY id_invoice
      , article)

在此处查看：http://sqlfiddle.com/#!4/f96adf/14

Answer 4

首先，您必须通过进行2次查询将实际与订购分开，然后您必须将订单连接到实际的..这样的事情

select 
   Recived.ID, 
   Recived.ID_Invoice,
   Recived.Article,
   Recived.Quantity - Ordered.Quantity as Quantity
from
   (select * from dataTable where Status is null) as Ordered
   left join (select * from  dataTable where Status = 'C')  as Recived on (Ordered.ID_Invoice = Recived.ID_Invoice and Ordered.Article = Recived.Article )

请注意！如果您在“左连接”中使用每个文章的ID而不是比较varchars，那么您会更好。

这是一个小提琴示例： http://sqlfiddle.com/#!2/16666/1

找出两组记录之间的差异

4 个答案: