Question

问题陈述：

我的表格中有Product_id和Quantity列假设product_id A有2个单位，B有3个单位等

如何创建一个包含2行Product_id A，3行Product_id B的表？

Answer 1

我是基于递归公用表表达式进行此练习的：

;WITH CTE (Vals) 
AS (
SELECT 1 
 UNION ALL
SELECT 1 + Vals
FROM CTE WHERE Vals< 99
   )
SELECT Product_id
FROM       Mytable A 
INNER JOIN CTE C   ON C.Vals <= A.Quantity
ORDER BY A.Product_id

假设数量＆lt; 99

可以帮到你

Answer 2

这对我有用，在您的示例中进行了测试：

WITH tally(n) AS (SELECT 1 UNION ALL SELECT n+1 FROM tally WHERE n<100) 

SELECT Product_id, 1 as Quantity 
FROM MyTable CROSS JOIN tally 
WHERE n<=quantity 
ORDER BY Product_id;

在sql中爆炸表

2 个答案: