Joe Celko's SQL for Smarties, 3rd Edition

24.6. Summation of a Series

While this topic is a bit more mathematical than most SQL programmers actually have to use in their work, it does demonstrate the power of SQL and a little knowledge of some basic college math.

The summation of a series builds a running total of the values in a table and shows the cumulative total for each value in the series. Let’s create a table and some sample data.

CREATE TABLE Series
(seq_nbr INTEGER NOT NULL PRIMARY KEY,
val INTEGER NOT NULL,
answer INTEGER  -- null means not computed yet
);

 Sequences
 seq_nbr     val  answer
 =======================
   1          6       6
   2         41      47
   3         12      59
   4         51     110
   5         21     131
   6         70     201
   7         79     280
   8         62     342
   ...

This simple summation is not a problem.

UPDATE Series SET answer = (SELECT SUM(R1.val) FROM Series ...