select the first observation by id

[sasphd]

hello 

I want to select the first observation by secid and grp. I try this but it give me the first observation by secid only

data first_by_group;
	set rolling12;
	by secid grp;
 
	if first.secid and first.grp then output;
run;

[PaigeMiller · Accepted solution]

if first.grp then output;

This give the first observation whenever GRP changes.

The way you had it written, you only get the first observation when BOTH secid and grp change.