How can I only get the last row that is grouped by 2 variables?

[aalluru]

I have the following data:

ID Flag Date Details

1   N     1/1    abc

1   N     1/2    efg

1   Y     1/1    hij

2   N    1/3     lmo

This dataset is already sorted by ID, flag and date (ascending order) using proc sort. I want to now only output the last row in every ID, flag combination as follows:

ID Flag Date Details

1   N    1/2     efg

1   Y    1/1     hij

2   N    1/3    lmo

[Tom · Accepted solution]

Just use BY group processing.  You want the last one per ID FLAG group.

data want;
  set have;
  by ID Flag Date;
  if last.flag;
run;

[aalluru]

that was easier than I thought. Thanks!