T-SQL using SUM for a running total - sql

Question

I have a simple table with some dummy data setup like:
|id|user|value|
---------------
1 John 2
2 Ted 1
3 John 4
4 Ted 2
I can select a running total by executing the following sql(MSSQL 2008) statement:
SELECT a.id, a.user, a.value, SUM(b.value) AS total
FROM table a INNER JOIN table b
ON a.id >= b.id
AND a.user = b.user
GROUP BY a.id, a.user, a.value
ORDER BY a.id
This will give me results like:
|id|user|value|total|
---------------------
1 John 2 2
3 John 4 6
2 Ted 1 1
4 Ted 2 3
Now is it possible to only retrieve the most recent rows for each user? So the result would be:
|id|user|value|total|
---------------------
3 John 4 6
4 Ted 2 3
Am I going about this the right way? any suggestions or a new path to follow would be great!

Answer 1

No join is needed, you can speed up the query this way:
select id, [user], value, total
from
(
select id, [user], value,
row_number() over (partition by [user] order by id desc) rn,
sum(value) over (partition by [user]) total
from users
) a
where rn = 1

Answer 2

try this:
;with cte as
(SELECT a.id, a.[user], a.value, SUM(b.value) AS total
FROM users a INNER JOIN users b
ON a.id >= b.id
AND a.[user] = b.[user]
GROUP BY a.id, a.[user], a.value
),
cte1 as (select *,ROW_NUMBER() over (partition by [user]
order by total desc) as row_num
from cte)
select id,[user],value,total from cte1 where row_num=1
SQL Fiddle Demo

Answer 3

add where statement:
select * from
(
your select statement
) t
where t.id in (select max(id) from table group by user)
also you can use this query:
SELECT a.id, a.user, a.value,
(select max(b.value) from table b where b.user=a.user) AS total
FROM table a
where a.id in (select max(id) from table group by user)
ORDER BY a.id

Answer 4

Adding a right join would perform better than nested select.
Or even simpler:
SELECT MAX(id), [user], MAX(value), SUM(value)
FROM table
GROUP BY [user]

Answer 5

Compatible with SQL Server 2008 or later
DECLARE #AnotherTbl TABLE
(
id INT
, somedate DATE
, somevalue DECIMAL(18, 4)
, runningtotal DECIMAL(18, 4)
)
INSERT INTO #AnotherTbl
(
id
, somedate
, somevalue
, runningtotal
)
SELECT LEDGER_ID
, LL.LEDGER_DocDate
, LL.LEDGER_Amount
, NULL
FROM ACC_Ledger LL
ORDER BY LL.LEDGER_DocDate
DECLARE #RunningTotal DECIMAL(18, 4)
SET #RunningTotal = 0
UPDATE #AnotherTbl
SET #RunningTotal=runningtotal = #RunningTotal + somevalue
FROM #AnotherTbl
SELECT *
FROM #AnotherTbl