sql – 根据列拆分2行或更多行上的行

我有个问题
如果我有一行看起来像这样

|ordernumber|qty|articlenumber|
|  123125213| 3 |fffff111     |

我怎么能把它分成三行,如下所示：

|ordernumber|qty|articlenumber|
|  123125213| 1 |fffff111     |
|  123125213| 1 |fffff111     |
|  123125213| 1 |fffff111     |

/ J

解决方法

您可以使用递归CTE：

WITH RCTE AS 
(
    SELECT  
        ordernumber,qty,articlenumber,qty AS L
    FROM Table1

    UNION ALL

    SELECT      
        ordernumber,1,L - 1 AS L
    FROM RCTE
    WHERE L>0
)
SELECT  ordernumber,articlenumber
FROM RCTE WHERE qty = 1

SQLFiddleDEMO

编辑：
根据Marek Grzenkowicz的回答和MatBailie的评论,全新的想法：

WITH CTE_Nums AS 
(
    SELECT MAX(qty) n FROM dbo.Table1
    UNION ALL
    SELECT n-1 FROM CTE_Nums
    WHERE n>1  
)
SELECT  ordernumber,1 AS qty,articlenumber
FROM dbo.Table1 t1
INNER JOIN CTE_Nums n ON t1.qty >= n.n

生成从1到最大(数量)的数字并在其上连接表.

SQLFiddle DEMO

原文地址：https://www.jb51.cc/mssql/74700.html