动态数据透视查询-SQL Server

Question

SQL小提琴：http://sqlfiddle.com/#!18/b871d/23

我有一个查询

-- DECLARE @Startdate datetime,
-- @Enddate datetime

WITH Table1 AS
(
select 
ID,
ItemNumber,
CAST(year(DateSold) AS VARCHAR(4)) + ' ' + DATENAME(m, DateSold) AS 
[DateSold2],
Qty
-- Price,
-- Cost
from ItemOrder
)

select * from Table1
pivot (sum(Qty) for[DateSold2] IN ([2018 August], [2018 July], [2018 June])) 
as d

结果：

| ID | ItemNumber |             DateSold | 2018 August | 2018 July | 2018 June |
|----|------------|----------------------|-------------|-----------|-----------|
|  1 |        145 | 2018-08-06T00:00:00Z |           5 |    (null) |    (null) |
|  2 |        145 | 2018-07-04T00:00:00Z |      (null) |         5 |    (null) |
|  3 |        145 | 2018-06-06T00:00:00Z |      (null) |    (null) |         5 |

我该如何动态地进行调整？例如用户可以输入任何日期范围，这需要在这几个月内进行调整。

此行

pivot (sum(Qty) for[DateSold2] IN ([2018 August], [2018 July], [2018 June])) 

我该如何创建一个不知道几个月的查询？