[SQL] variables in SQL??

[Francisco Hernandez]

anyone know if SQL has variables?

what im trying to do is have a Sum of a colum.. as it goes forwards with the
cursor..
like so:

Price|Sum
5|5
4|9
10|19
2|21
7|28

i can do it in the accessing language.. like PHP, Python, Perl etc..
but i wanted to know if the actuall DB could do it?
any ideas?