Sql 用未来日期填充行，即使没有值

故事：

我的数据集如下所示：

+---------+------+-----------------+---------+
|  Date   | Cost | Revenue   Month | Revenue |
+---------+------+-----------------+---------+
| 2018-01 |   20 | 2018-02         |      20 |
| 2018-01 |   20 | 2018-03         |     100 |
| 2018-02 |    5 | 2018-03         |      15 |
| 2018-02 |    5 | 2018-04         |      25 |
+---------+------+-----------------+---------+

基本上，日期列表示初始投资，收入月表示由于投资月而产生的资金。我希望在本月之前的每个后续月份填写收入月的行，并强制收入显示为0，即2020年8月

目标：

我尝试的是：

我建立了这个理货日期表

DROP TABLE IF EXISTS ##dates
CREATE TABLE ##dates ([date] Date)
DECLARE @dIncr DATE = '01/01/2018'
DECLARE @dEnd DATE = cast(getdate() as date)
WHILE (@dIncr <= @dEnd)
BEGIN
  INSERT INTO ##dates ([date]) VALUES (@dIncr)
  SELECT @dIncr = DATEADD(month,1,@dIncr)
END

---

但我一直坚持这一点。

如果您想在数据中添加两个月，您可以使用union all：

编辑：

使用递归CTE：

with cte as (
      select date, cost, max(returning_month) as returning_month, revenue, product, 0 as lev
      from t
      group by date, cost, revenue, product
      union all
      select date, cost, dateadd(month, 1, returning_month), revenue, product, lev + 1
      from cte
      where returning_month < getdate()
     )
select date, cost, returning_month, revenue, product
from cte
where lev > 0;

---

不只是两个月，而是直到本月的所有后续月份

select  Date, Cost, Returning_Month, Revenue, Product 
from t
union all
select  Date, Cost, dateadd(month, v.n, Returning_Month), 0 as Revenue, Product 
from (select date, cost, max(returning_month) as returning_month, revenue, product
      from t
      group by date, cost, revenue, product
     ) t cross apply
     (values (1), (2)) v(n);

with cte as (
      select date, cost, max(returning_month) as returning_month, revenue, product, 0 as lev
      from t
      group by date, cost, revenue, product
      union all
      select date, cost, dateadd(month, 1, returning_month), revenue, product, lev + 1
      from cte
      where returning_month < getdate()
     )
select date, cost, returning_month, revenue, product
from cte
where lev > 0;