## Subset data based on the value included in the repeated observations

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Super Contributor
Posts: 335

# Subset data based on the value included in the repeated observations

I have patients in my data with repeated observations. "uid"=unique identifier of patients. dos=date of survey. I'd like to subset data where patients have future date of survey (2019). Below approach outputs the rows only where dos=2019 but not along with previous years of information which I need to have to investigate the source of error.

Your help is appreciated to come up with data "want" from the code block below. Using SAS 9.4.

``````data have;
input uid dos;
cards;
1 2015
1 2016
1 2019
2 2017
2 2018
3 2019
4 2015
4 2016
4 2017
5 2015
;

data want;
input uid dos;
cards;
1 2015
1 2016
1 2019
3 2019
;

proc sort data=have;
by uid;
run;
data wrong; set have;
by uid;
if dos in (2019) then output;
run;``````

Accepted Solutions
Solution
‎04-09-2018 03:23 PM
Super User
Posts: 23,305

## Re: Subset data based on the value included in the repeated observations

``````proc sql;

create table want as
select * from have
where uid in
(select uid from have where dos=2019);

quit;
``````

All Replies
Solution
‎04-09-2018 03:23 PM
Super User
Posts: 23,305

## Re: Subset data based on the value included in the repeated observations

``````proc sql;

create table want as
select * from have
where uid in
(select uid from have where dos=2019);

quit;
``````
Super Contributor
Posts: 335

## Re: Subset data based on the value included in the repeated observations

worked out! but why? trying to visualize how SAS is calling data here
Super User
Posts: 23,305

## Re: Subset data based on the value included in the repeated observations

``````proc sql;

create table want as
select * from have
where uid in /*selects only IDS from this list*/
(select distinct uid from have where dos=2019); *<- this creates a list of IDs where it is 2019, should add the DISTNCT word here;

quit;``````
☑ This topic is solved.