Problem

Question

Problem

In my sql-server-2014 I store projects in a table with the columns:

Startdate .. | Enddate ....| Projectname .................| Volume
2017-02-13 | 2017-04-12 | GenerateRevenue .........| 20.02
2017-04-02 | 2018-01-01 | BuildRevenueGenerator | 300.044
2017-05-23 | 2018-03-19 | HarvestRevenue ............| 434.009

I need a SELECT to give me one row per month of the project for each project. the days of the month don't have to be considered.

Extra

Ideally the logic of the SELECT allows me both to calculate the monthly volume and also the difference between each month and the previous.

Also...

I know I can map it on a temporary calendar table, but that tends to get bloated and complex very fast. Im really looking for a better way to solve this problem.

Solution

Gordons solution worked very nicely and it doesn't require a second table or mapping on a calendar of some sort. Although I had to change a few things, like making sure both sides of the union have the same SELECT.

Here my adapted version:

with cte as (
  select startdate as mondate, enddate, projectName, volume 
  from projects
  union all
  select dateadd(month, 1, mondate), enddate, projectName, volume
  from cte
  where eomonth(dateadd(month, 1, mondate)) <= eomonth(enddate)
)
select * from cte;

Volume monthly can be achieved by replacing volume with:

CAST(Cast(volume AS DECIMAL) / Cast(Datediff(month, 
startdate,enddate)+ 1 AS DECIMAL) AS DECIMAL(15, 2)) 
END AS [volumeMonthly]

Answer 1

Another option is with an ad-hoc tally table

Example

-- Some Sample Data
Declare @YourTable table (StartDate date,EndDate date,ProjectName varchar(50), Volume float)
Insert Into @YourTable values
 ('2017-03-15','2017-07-25','Project X',25)
,('2017-04-01','2017-06-30','Project Y',50)

-- Set Your Desired Date Range   
Declare @Date1 date = '2017-01-01'
Declare @Date2 date = '2017-12-31'

Select Period = D
      ,B.*
      ,MonthlyVolume = sum(Volume) over (Partition By convert(varchar(6),D,112))
 From (Select Top (DateDiff(MONTH,@Date1,@Date2)+1) D=DateAdd(MONTH,-1+Row_Number() Over (Order By (Select Null)),@Date1) 
        From  master..spt_values n1
      ) A
 Join @YourTable B on convert(varchar(6),D,112) between convert(varchar(6),StartDate,112) and convert(varchar(6),EndDate,112)
 Order by Period,ProjectName

Returns

Note: Use a LEFT JOIN to see gaps

Answer 2

You can use a recursive subquery to expand the rows for each project, based on the table:

with cte as (
      select stardate as mondate, p.*
      from projects
      union all
      select dateadd(month, 1, mondate), . . .  -- whatever columns you want here
      from cte
      where eomonth(dateadd(month, 1, mondate)) <= eomonth(enddate)
    )
select *
from cte;

I'm not sure if this actually answers your question. When I first read the question, I figured the table had one row per project.

Answer 3

Using a couple of common table expressions, an adhoc calendar table for months and lag() (SQL Server 2012+) for the final delta calculation:

create table projects (id int identity(1,1), StartDate date, EndDate date, ProjectName varchar(32), Volume float);
insert into projects values ('20170101','20170330','SO Q1',240),('20170214','20170601','EX Q2',120)

declare @StartDate date = '20170101'
      , @EndDate   date = '20170731';
;with Months as (
  select top (datediff(month,@startdate,@enddate)+1) 
        MonthStart = dateadd(month, row_number() over (order by number) -1, @StartDate)
      , MonthEnd = dateadd(day,-1,dateadd(month, row_number() over (order by number), @StartDate))
    from master.dbo.spt_values
  )
, ProjectMonthlyVolume as (
  select p.*
    , MonthlyVolume = Volume/(datediff(month,p.StartDate,p.EndDate)+1)
    , m.MonthStart
  from Months m
    left join Projects p
      on p.EndDate >= m.MonthStart
     and p.StartDate <= m.MonthEnd
)
select 
    MonthStart = convert(char(7),MonthStart,120)
  , MonthlyVolume = isnull(sum(MonthlyVolume),0)
  , Delta = isnull(sum(MonthlyVolume),0) - lag(Sum(MonthlyVolume)) over (order by MonthStart)
from ProjectMonthlyVolume pmv
group by MonthStart

rextester demo: http://rextester.com/DZL54787

returns:

+------------+---------------+-------+
| MonthStart | MonthlyVolume | Delta |
+------------+---------------+-------+
| 2017-01    |            80 | NULL  |
| 2017-02    |           104 | 24    |
| 2017-03    |           104 | 0     |
| 2017-04    |            24 | -80   |
| 2017-05    |            24 | 0     |
| 2017-06    |            24 | 0     |
| 2017-07    |             0 | -24   |
+------------+---------------+-------+

Select Multiple Rows from Timespan

Problem

Extra

Also...

Solution

3 个答案: