Sql server SQL-如何根据现有数据集中的日期范围为每个月生成行？

假设我有一个数据集：

rowID |  dateStart  |   dateEnd  | Year | Month
121   | 2013-10-03  | 2013-12-03 | NULL | NULL
143   | 2013-12-11  | 2014-03-11 | NULL | NULL
322   | 2014-01-02  | 2014-02-11 | NULL | NULL

我希望sql根据dateStart和dateEnd生成以下数据源。注意年份和月份分组

rowID |  dateStart  |   dateEnd  | Year | Month
121   | 2013-10-03  | 2013-12-03 | 2013 |   10
121   | 2013-10-03  | 2013-12-03 | 2013 |   11
121   | 2013-10-03  | 2013-12-03 | 2013 |   12
143   | 2013-12-11  | 2014-03-11 | 2013 |   12
143   | 2013-12-11  | 2014-03-11 | 2014 |    1
143   | 2013-12-11  | 2014-03-11 | 2014 |    2
143   | 2013-12-11  | 2014-03-11 | 2014 |    3
322   | 2014-01-02  | 2014-02-11 | 2014 |    1
322   | 2014-01-02  | 2014-02-11 | 2014 |    2

---

我很难在这件事上下定决心。有什么想法吗？

我发现解决这些问题最简单的方法是创建一个整数列表，然后用它来增加日期。以下是一个例子：

with nums as (
      select 0 as n
      union all
      select n + 1 as n
      from nums
      where n < 11
     )
select rowid, datestart, dateend,
       year(dateadd(month, n.n, datestart)) as yr,
       month(dateadd(month, n.n, datestart)) as mon
from table t join
     nums n
     on dateadd(month, n.n - 1, datestart) <= dateend;

---

首先，创建一个表值函数，该函数采用两个日期并将年和月作为表返回：

create function dbo.YearMonths(@StartDate DateTime, @EndDate DateTime)
returns @YearMonths table
([Year] int,
[Month] int)
as
begin

    set @EndDate = DATEADD(month, 1, @EndDate)
    while (@StartDate < @EndDate)
    begin

    insert into @YearMonths
    select YEAR(@StartDate), MONTH(@StartDate)  

    set @StartDate = DATEADD(month, 1, @StartDate)

    end

return
end

返回：

然后你会像这样加入它，得到你想要的：

select m.*, ym.Year, ym.Month
from myTable m
cross apply dbo.YearMonths(dateStart, dateEnd) ym

试试这个：

declare @months table(mth int)
insert into @months values(1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12)

declare @calendar table(yr int,mth int)
insert into @calendar
select distinct year(datestart),mth
from tbl cross join @months
union
select distinct year(dateend),mth
from tbl cross join @months

select t.rowID, t.datestart, t.dateend, y.yr [Year], y.mth [Month] 
from
yourtable t
inner join @calendar y on year(datestart) = yr or year(dateend) = yr
where 
(mth >= month(datestart) and mth <= month(dateend) and year(datestart) = year(dateend))
or 
(year(datestart) < year(dateend)) 
 and 
 (year(datestart) = yr and mth >= month(datestart) --All months of start year
 or 
 (year(dateend) = yr and mth <= month(dateend))) -- All months of end year
order by t.rowID, [Year],[Month]

---

我们创建了一个“日历表”，其中列出了源表中存在的所有月份和年份组合。然后，我们根据年份将源表加入日历表，并根据需要进行筛选。

喜欢所有3个响应！我选择Gordon的，因为它允许我进行外部连接，并忽略具有额外过滤参数的行。我没有要求这样做，但后来我能够实现它。JBrooks解决方案非常棒，因为它占用的空间更小，并且允许我利用函数，而shree的解决方案对于我更大的项目来说有点过于冗长，但仍然完全满足了我的需要。谢谢大家!！在NUM中将10替换为11，否则它将在12个月的范围内跳过一个月。也替换为：<替换为

declare @months table(mth int)
insert into @months values(1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12)

declare @calendar table(yr int,mth int)
insert into @calendar
select distinct year(datestart),mth
from tbl cross join @months
union
select distinct year(dateend),mth
from tbl cross join @months

select t.rowID, t.datestart, t.dateend, y.yr [Year], y.mth [Month] 
from
yourtable t
inner join @calendar y on year(datestart) = yr or year(dateend) = yr
where 
(mth >= month(datestart) and mth <= month(dateend) and year(datestart) = year(dateend))
or 
(year(datestart) < year(dateend)) 
 and 
 (year(datestart) = yr and mth >= month(datestart) --All months of start year
 or 
 (year(dateend) = yr and mth <= month(dateend))) -- All months of end year
order by t.rowID, [Year],[Month]