Conditional SUM for rows

[Demographer]

Hello,

I have a dataset that looks like this:

year	orig	dest	flow
1990	AT	BE	456
1990	AT	DE	356
1990	AT	DE	21
1990	BE	DE	235

I would like to sum the column "flow" when year, orig and dest have the same value. For instance, in that example, the dataset should become:

year	orig	dest	flow
1990	AT	BE	456
1990	AT	DE	377
1990	BE	DE	235

Is there a simple way to do this?

[RW9 · Accepted solution]

Post test data in the form of a datastep!

proc sql;
  create table WANT as
  select  YEAR,
          ORIG,
          DEST,
          sum(FLOW) as FLOW
  from    HAVE
  group by YEAR,ORIG,DEST;
quit;

As  a guess.