You can use GROUP BY same as in standard SQL.
Or use PROC MEANS.
You can see an illustration of PROC MEANS by running this code.
*Create summary statistics for a dataset by a 'grouping' variable and store it in a dataset;
*Generate sample fake data;
data have;
input ID feature1 feature2 feature3;
cards;
1 7.72 5.43 4.35
1 5.54 2.25 8.22
1 4.43 6.75 2.22
1 3.22 3.21 7.31
2 6.72 2.86 6.11
2 5.89 4.25 5.25
2 3.43 7.30 8.21
2 1.22 3.55 6.55
;
run;
*Create summary data;
proc means data=have noprint;
by id;
var feature1-feature3;
output out=want median= var= mean= /autoname;
run;
*Show for display;
proc print data=want;
run;
*First done here:https://communities.sas.com/t5/General-SAS-Programming/Getting-creating-new-summary-variables-longitudinal-data/m-p/347940/highlight/false#M44842;
*Another way to present data is as follows;
proc means data=have stackods nway n min max mean median std p5 p95;
by id;
var feature1-feature3;
ods output summary=want2;
run;
*Show for display;
proc print data=want2;
run;