How to sum values of a column based on the increment values of another column in SQL

Question

I have a table like below, now I want to sum up the values in column count as the values in day increases. I tried to query like below but it isn't working. As I am new to SQL just confused to create query which works for the above query.

Table:-

id     count  days
78112   4      2
78112   1      3
78112   2      5
8560    4      2
8560    4      4
9503    5      1
9503    3      2
9503    2      4
9503    5      6

Query:-

select id,sum(count),days from test group by id,days

This returns:-

id     count  days
78112   4      2
78112   1      3
78112   2      5
8560    4      2
8560    4      4
9503    5      1
9503    3      2
9503    2      4
9503    5      6

Excepted Output:-

id     count  days
78112   4      2
78112   5      3
78112   7      5
8560    4      2
8560    8      4
9503    5      1
9503    8      2
9503    10      4
9503    15      6

Answer 1

You need a running total partitioned by id.

Select   id
        ,sum(count) over(partition by id order by days) as count
        ,days

From     t
order by cast(id as varchar(99)), days

id	count	days
78112	4	2
78112	5	3
78112	7	5
8560	4	2
8560	8	4
9503	5	1
9503	8	2
9503	10	4
9503	15	6

Fiddle