SQL Server 2012 - Running Total

Question

I am trying to calculate a running total on a table, while limiting the number of rows returned by the query.

My table looks something like this:

create table TestTable
(
  id int,
  somedate date,
  somevalue int
)

insert into TestTable values
(45,     '01/Jan/09',   3),
(23,     '08/Jan/09',   5),
(12,     '02/Feb/09',   0),
(77,     '14/Feb/09',   7),
(39,     '20/Feb/09',   34),
(33,     '02/Mar/09',   6)

And I can get all the rows with a running total of "value" like this:

select id,
       somedate,
       somevalue,
       sum(somevalue) over(order by somedate) as runningtotal
from TestTable

I want to limit the results returned to a specific date range, while still having the running total get computed from the beginning of the table. So, for example, I want all rows with a date on or after 20/Feb/09. Then, I would want my result set to look like:

39  20/Feb/09  49
33  02/Mar/09  55

But if i just do a where somedate > 20/Feb/09, then I get

39  20/Feb/09  34
33  02/Mar/09  40

which is not what I want, because it's computing the running total only within the window.

Is there a way to get what I want?

Answer 1

You could do this with a subquery:

SELECT *
FROM (select id,
       somedate,
       somevalue,
       sum(somevalue) over(order by somedate) as runningtotal
      from TestTable
      )sub
WHERE somedate > '2009-02-20'