declare @t table
(
id int,
SomeNumt int
)
insert into @t
select 1,10
union
select 2,12
union
select 3,3
union
select 4,15
union
select 5,23
select * from @t
the above select returns me the following.
id SomeNumt
1 10
2 12
3 3
4 15
5 23
How do I get the following:
id srome CumSrome
1 10 10
2 12 22
3 3 25
4 15 40
5 23 63
select t1.id, t1.SomeNumt, SUM(t2.SomeNumt) as sum
from @t t1
inner join @t t2 on t1.id >= t2.id
group by t1.id, t1.SomeNumt
order by t1.id
Output
| ID | SOMENUMT | SUM |
-----------------------
| 1 | 10 | 10 |
| 2 | 12 | 22 |
| 3 | 3 | 25 |
| 4 | 15 | 40 |
| 5 | 23 | 63 |
Edit: this is a generalized solution that will work across most db platforms. When there is a better solution available for your specific platform (e.g., gareth's), use it!
The latest version of SQL Server (2012) permits the following.
SELECT
RowID,
Col1,
SUM(Col1) OVER(ORDER BY RowId ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS Col2
FROM tablehh
ORDER BY RowId
or
SELECT
GroupID,
RowID,
Col1,
SUM(Col1) OVER(PARTITION BY GroupID ORDER BY RowId ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS Col2
FROM tablehh
ORDER BY RowId
This is even faster. Partitioned version completes in 34 seconds over 5 million rows for me.
Thanks to Peso, who commented on the SQL Team thread referred to in another answer.
For SQL Server 2012 onwards it could be easy:
SELECT id, SomeNumt, sum(SomeNumt) OVER (ORDER BY id) as CumSrome FROM @t
because ORDER BY clause for SUM by default means RANGE UNBOUNDED PRECEDING AND CURRENT ROW for window frame ("General Remarks" at https://msdn.microsoft.com/en-us/library/ms189461.aspx)
Let's first create a table with dummy data:
Create Table CUMULATIVESUM (id tinyint , SomeValue tinyint)
Now let's insert some data into the table;
Insert Into CUMULATIVESUM
Select 1, 10 union
Select 2, 2 union
Select 3, 6 union
Select 4, 10
Here I am joining same table (self joining)
Select c1.ID, c1.SomeValue, c2.SomeValue
From CumulativeSum c1, CumulativeSum c2
Where c1.id >= c2.ID
Order By c1.id Asc
Result:
ID SomeValue SomeValue
-------------------------
1 10 10
2 2 10
2 2 2
3 6 10
3 6 2
3 6 6
4 10 10
4 10 2
4 10 6
4 10 10
Here we go now just sum the Somevalue of t2 and we`ll get the answer:
Select c1.ID, c1.SomeValue, Sum(c2.SomeValue) CumulativeSumValue
From CumulativeSum c1, CumulativeSum c2
Where c1.id >= c2.ID
Group By c1.ID, c1.SomeValue
Order By c1.id Asc
For SQL Server 2012 and above (much better performance):
Select
c1.ID, c1.SomeValue,
Sum (SomeValue) Over (Order By c1.ID )
From CumulativeSum c1
Order By c1.id Asc
Desired result:
ID SomeValue CumlativeSumValue
---------------------------------
1 10 10
2 2 12
3 6 18
4 10 28
Drop Table CumulativeSum
A CTE version, just for fun:
;
WITH abcd
AS ( SELECT id
,SomeNumt
,SomeNumt AS MySum
FROM @t
WHERE id = 1
UNION ALL
SELECT t.id
,t.SomeNumt
,t.SomeNumt + a.MySum AS MySum
FROM @t AS t
JOIN abcd AS a ON a.id = t.id - 1
)
SELECT * FROM abcd
OPTION ( MAXRECURSION 1000 ) -- limit recursion here, or 0 for no limit.
Returns:
id SomeNumt MySum
----------- ----------- -----------
1 10 10
2 12 22
3 3 25
4 15 40
5 23 63
Late answer but showing one more possibility...
Cumulative Sum generation can be more optimized with the CROSS APPLY logic.
Works better than the INNER JOIN & OVER Clause when analyzed the actual query plan ...
/* Create table & populate data */
IF OBJECT_ID('tempdb..#TMP') IS NOT NULL
DROP TABLE #TMP
SELECT * INTO #TMP
FROM (
SELECT 1 AS id
UNION
SELECT 2 AS id
UNION
SELECT 3 AS id
UNION
SELECT 4 AS id
UNION
SELECT 5 AS id
) Tab
/* Using CROSS APPLY
Query cost relative to the batch 17%
*/
SELECT T1.id,
T2.CumSum
FROM #TMP T1
CROSS APPLY (
SELECT SUM(T2.id) AS CumSum
FROM #TMP T2
WHERE T1.id >= T2.id
) T2
/* Using INNER JOIN
Query cost relative to the batch 46%
*/
SELECT T1.id,
SUM(T2.id) CumSum
FROM #TMP T1
INNER JOIN #TMP T2
ON T1.id > = T2.id
GROUP BY T1.id
/* Using OVER clause
Query cost relative to the batch 37%
*/
SELECT T1.id,
SUM(T1.id) OVER( PARTITION BY id)
FROM #TMP T1
Output:-
id CumSum
------- -------
1 1
2 3
3 6
4 10
5 15
There is a much faster CTE implementation available in this excellent post: http://weblogs.sqlteam.com/mladenp/archive/2009/07/28/SQL-Server-2005-Fast-Running-Totals.aspx
The problem in this thread can be expressed like this:
DECLARE @RT INT
SELECT @RT = 0
;
WITH abcd
AS ( SELECT TOP 100 percent
id
,SomeNumt
,MySum
order by id
)
update abcd
set @RT = MySum = @RT + SomeNumt
output inserted.*
The SQL solution wich combines "ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW" and "SUM" did exactly what i wanted to achieve. Thank you so much!
If it can help anyone, here was my case. I wanted to cumulate +1 in a column whenever a maker is found as "Some Maker" (example). If not, no increment but show previous increment result.
So this piece of SQL:
SUM( CASE [rmaker] WHEN 'Some Maker' THEN 1 ELSE 0 END)
OVER
(PARTITION BY UserID ORDER BY UserID,[rrank] ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS Cumul_CNT
Allowed me to get something like this:
User 1 Rank1 MakerA 0
User 1 Rank2 MakerB 0
User 1 Rank3 Some Maker 1
User 1 Rank4 Some Maker 2
User 1 Rank5 MakerC 2
User 1 Rank6 Some Maker 3
User 2 Rank1 MakerA 0
User 2 Rank2 SomeMaker 1
Explanation of above: It starts the count of "some maker" with 0, Some Maker is found and we do +1. For User 1, MakerC is found so we dont do +1 but instead vertical count of Some Maker is stuck to 2 until next row. Partitioning is by User so when we change user, cumulative count is back to zero.
I am at work, I dont want any merit on this answer, just say thank you and show my example in case someone is in the same situation. I was trying to combine SUM and PARTITION but the amazing syntax "ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW" completed the task.
Thanks! Groaker
