All values for only most recent occurrence - sas

Question

I am trying to extract all the Time occurrences for only the recent visit. Can someone help me with the code please.
Here is my data:
Obs Name Date Time
1 Bob 2017090 1305
2 Bob 2017090 1015
3 Bob 2017081 0810
4 Bob 2017072 0602
5 Tom 2017090 1300
6 Tom 2017090 1010
7 Tom 2017090 0805
8 Tom 2017072 0607
9 Joe 2017085 1309
10 Joe 2017081 0815
I need the output as:
Obs Name Date Time
1 Bob 2017090 1305,1015
2 Tom 2017090 1300,1010,0805
3 Joe 2017085 1309
Right now my code is designed to give me only one recent entry:
DATA OUT2;
SET INP1;
BY DATE;
IF FIRST.DATE THEN OUTPUT OUT2;
RETURN;

Answer 1

I would first sort the data by name and date. Then I would transpose and process the results.
proc sort data=have;
by name date;
run;
proc transpose data=have out=temp1;
by name date;
var value;
run;
data want;
set temp1;
by name date;
if last.name;
format value $2000.;
value = catx(',',of col:);
drop col: _name_;
run;
You may want to further process the new VALUE to remove excess commas (,) and missing value .'s.

Answer 2

Very similar to the question yesterday from another user, you can use quite a few solutions here.
SQL again is the easiest; this is not valid ANSI SQL and pretty much only SAS supports this, but it does work in SAS:
proc sql;
select name, date, time
from have
group by name
having date=max(date);
quit;
Even though date and time are not on the group by it's legal in SAS to put them on the select, and then SAS automatically merges (inner joins) the result of select name, max(date) from have group by name having date=max(date) to the original have dataset, returning multiple rows as needed. Then you'd want to collapse the rows, which I leave as an exercise for the reader.
You could also simply generate a table of maximum dates using any method you choose and then merge yourself. This is probably the easiest in practice to use, in particular including troubleshooting.
The DoW loop also appeals here. This is basically the precise SAS data step implementation of the SQL above. First iterate over that name, figure out the max, then iterate again and output the ones with that max.
proc sort data=have;
by name date;
run;
data want;
do _n_ = 1 by 1 until (last.name);
set have;
by name;
max_Date = max(max_date,date);
end;
do _n_ = 1 by 1 until (last.name);
set have;
by name;
if date=max_date then output;
end;
run;
Of course here you more easily collapse the rows, too:
data want;
length timelist $1024;
do _n_ = 1 by 1 until (last.name);
set have;
by name;
max_Date = max(max_date,date);
end;
do _n_ = 1 by 1 until (last.name);
set have;
by name;
if date=max_date then timelist=catx(',',timelist,time);
if last.name then output;
end;
run;

Answer 3

If the data is sorted then just retain the first date so you know which records to combine and output.
proc sort data=have ;
by name descending date time;
run;
data want ;
set have ;
by name descending date ;
length timex $200 ;
retain start timex;
if first.name then do;
start=date;
timex=' ';
end;
if date=start then do;
timex=catx(',',timex,time);
if last.date then do;
output;
call missing(start,timex);
end;
end;
drop start time ;
rename timex=time ;
run;