topic Re: Looping through rows of table in New SAS User

Looping through rows of table

jlin4 — Fri, 23 Jul 2021 17:04:37 GMT

Hi, supposed I have a list of IDs, presented in the form of a table, like work.id. For each ID, I wish to perform a set of operations that will return me either a "Y" or a "N". After which, I would like to add the returns to the table as a new column, such as in work.id_response.

May I enquire how should I go about doing so? Thank you!

data work.id;
input id$;
cards;
abc
def
ghi
jkl
;
run;

data work.id_response;
input id$ response$;
cards;
abc y
def y
ghi n
jkl n
;
run;

Re: Looping through rows of table

PaigeMiller — Fri, 23 Jul 2021 17:16:45 GMT

Something like this:

data want;
    set id;
    if condition=1 /* You need to type the real condition being tested*/ then response='Y'; 
    else response='N';
run;

Please note that the default behavior of a data step is to loop over all observations, so you don't need to program any loop.

Re: Looping through rows of table

Reeza — Fri, 23 Jul 2021 17:20:17 GMT

Depends on the "set of operations" needed in that step. If it's something as simple as checking if it's in a list of value a data step works fine. If you need to go look up something in three different table and factor in amounts over time that's a lot more complex.

Your use case is too simplistic to provide an answer 😞

This is an example of your simplistic case - SAS loops automatically through each row in a data set so no explicit loop or anything else is required.

data want;
set id;
if id in ('abc', 'def') then response = "y";
else response = "n";
run;

@jlin4 wrote:

Hi, supposed I have a list of IDs, presented in the form of a table, like work.id. For each ID, I wish to perform a set of operations that will return me either a "Y" or a "N". After which, I would like to add the returns to the table as a new column, such as in work.id_response.

May I enquire how should I go about doing so? Thank you!
data work.id;
input id$;
cards;
abc
def
ghi
jkl
;
run;
data work.id_response;
input id$ response$;
cards;
abc y
def y
ghi n
jkl n
;
run;

Re: Looping through rows of table

ballardw — Fri, 23 Jul 2021 17:19:10 GMT

What are the rules for adding "y" or "n"?

The data step "loops through rows" of a data set.

This adds a row number (actual loop count) to your data from the work.id dataset.

data work.id_row;
   set work.id;
   row = _n_;
run;

_n_ is an automatic variable that SAS creates as it counts how many times the data step executes, i.e. "loops".

Re: Looping through rows of table

jlin4 — Fri, 23 Jul 2021 18:31:51 GMT

thank you!

Re: Looping through rows of table

jlin4 — Fri, 23 Jul 2021 18:32:03 GMT

Thank you!

Re: Looping through rows of table

Reeza — Fri, 23 Jul 2021 20:26:17 GMT

If one of the responses here is the correct answer to your question please mark it as resolved.