在SQL Server中将列转换为行？

我有以下销售表（SQL Server 2017）（每种商品约20行）：

我想准备一个数据集，以便特定商店中的每个商品对应一行：

+---------+----------+---------------+---------------+---------+---------+-----------+-----------+--------+--------+
| good_id | store_id | week_number_1 | week_number_2 | promo_1 | promo_2 | holiday_1 | holiday_2 | sale_1 | sale_2 |
+---------+----------+---------------+---------------+---------+---------+-----------+-----------+--------+--------+
| 201712  | 255      | 1             | 2             | 1       | 0       | 0         | 0         | 2      | 0      |
+---------+----------+---------------+---------------+---------+---------+-----------+-----------+--------+--------+

我知道如何对具有唯一值的单个列执行此操作：

SELECT *
FROM
(
    SELECT [good_id],
           [store_id],
           [week_number],
           [sale]
    FROM table
    WHERE good_id = 201712
    AND store_id = 255
) AS SourceTable PIVOT(AVG([sale]) FOR [week_number] IN([1],
                                                         [2])) AS PivotTable

---

但是如何编写所需的代码，我还不明白

您可以使用条件聚合：

select good_id, store_id,
       max(case when week_number = 1 then promo end) as promo_1,
       max(case when week_number = 1 then holiday end) as holiday_1,
       max(case when week_number = 1 then sale end) as sale_1,
       max(case when week_number = 2 then promo end) as promo_2,
       max(case when week_number = 2 then holiday end) as holiday_2,
       max(case when week_number = 2 then sale end) as sale_2,
       . . . 
from table
group by good_id, store_id;

---

OP必须重复此操作大约20次！

select good_id, store_id,
       max(case when week_number = 1 then promo end) as promo_1,
       max(case when week_number = 1 then holiday end) as holiday_1,
       max(case when week_number = 1 then sale end) as sale_1,
       max(case when week_number = 2 then promo end) as promo_2,
       max(case when week_number = 2 then holiday end) as holiday_2,
       max(case when week_number = 2 then sale end) as sale_2,
       . . . 
from table
group by good_id, store_id;