SQL Server: Adding up a column sequentially

Question

Suppose I have the following data:

ID        Characteristic     Number
1               A               3
2               B               4
3               A               1
4               A               6

I want a resulting table that adds up the number column like this:

ID        Characteristic     Number          Sum
1               A               3             3
2               B               4             7
3               A               1             8
4               A               6             14

Basically, it adds the new number to the previous sum and is ordered by the ID.

Thanks in advance for the help.

Answer 1

In SQL Server 2012+, you can just use the ANSI-standard cumulative sum function:

select id, characteristic, number, sum(number) over (order by id) as [sum]
from t;

Answer 2

In SQL (>2012), you can just use the sum function:

select id, characteristic, number, sum(number) over (order by id) as [sum]
from t;

Answer 3

Std cumulative sum

select t1.*, SUM(t2.Nuber) as sum
from table t1
inner join table t2 on t1.id >= t2.id
group by t1.id, t1.Number
order by t1.id;