Group identical ids and indicate first and last date of an incident per id

[AnnaNZ]

Hi

I have a dataset with many identical IDs, which were taken up at different times (datetime 18). 

I want to know the earlierst and the last time that an ID was taken up ( and calculate the timeinterval).

So some REFER_ID appeas on multiple different times (LAT_UPDT_DT) as indicted below in red. 

The aim is to calculate the timedifference between the fist time and the last time they appear. 

What I have: 

proc sort data = main_vic; by REFER_ID ;
run;

proc sql;
  create table want as
    select min(LST_UPDT_DT) as min_date format=datetime18.,
                 max(LST_UPDT_DT) as max_date format=datetime18.
             from main_vic;
quit;

This of course gives me only the first and the last date of all REFER_ID

How can I group REFER_ID so  that I always receive the first and last visit of that REFER_ID?

I tried to add a by statement, but was not sucessful. 

Any ideas are highly appreaciated. 

[Jagadishkatam · Accepted solution]

Please try the below code, it is untested but should work

also included the difference in days and hours

proc means data=have ;
class refer_id;
var lst_updt_dt;
output out=want min=min max=max;
run;

data want2;
set want;
diffinhours=(max-min)/3600;
diffindays=(max-min)/86400;
run;

[AnnaNZ]

Great solution for this problem, thanks a lot !

[kiranv_]

Something like this. I took a similar example instead of date time. I have used somenum

data abc;
input id someotherval $ somenum;
datalines;
1 a 20
1 b 30
1 c 40
2 a 40
2 a 50
2 a 45
;
run;

proc sql;
select a.*, max(somenum)-min(somenum) as diff from abc a
group by id;

;
quit;

[Ksharp]

data abc;
input id someotherval $ somenum;
datalines;
1 a 20
1 b 30
1 c 40
2 a 40
2 a 50
2 a 45
;
run;

proc sql;
select a.*, range(somenum) as diff from abc as a
group by id;
;
quit;