如何通过在SQL的第一列中添加值来创建第二列？

Question

Below given table ABC has column Num and second column should be created by adding the values in column first. Table ABC

Num
1
2
3
4
5

Output

Num  Num2
1    1
2    3
3    6
4    9
5    12

Answer 1

Oracle supports the ANSI standard method of calculating cumulative sums:

select num, sum(num) over (order by num)
from t;

Answer 2

And you can do this in MYSQL

SELECT    T.* ,
             @SUM:=@SUM + T.num AS RunningTotal
FROM     (SELECT @SUM:=0) S,T