SAS Transpose Comma Separated Field - sas

Question

This is a follow-up to an earlier question of mine.
Transposing Comma-delimited field
The answer I got worked for the specific case, but now I have a much larger dataset, so reading it in a datalines statement is not an option. I have a dataset similar to the one created by this process:
data MAIN;
input ID STATUS STATE $;
cards;
123 7 AL,NC,SC,NY
456 6 AL,NC
789 7 ALL
;
run;
There are two problems here:
1: I need a separate row for each state in the STATE column
2: Notice the third observation says 'ALL'. I need to replace that with a list of the specific states, which I can get from a separate dataset (below).
data STATES;
input STATE $;
cards;
AL
NC
SC
NY
TX
;
run;
So, here is the process I am attempting that doesn't seem to be working.
First, I create a list of the STATES needed for the imputation, and a count of said states.
proc sql;
select distinct STATE into :all_states separated by ','
from STATES;
select count(distinct STATE) into :count_states
from STATES;
quit;
Second, I try to impute that list where the 'ALL' value appears for STATE. This is where the first error appears. How can I ensure that the variable STATE is long enough for the new value? Also, how do I handle the commas?
data x_MAIN;
set MAIN;
if STATE='ALL' then STATE="&all_states.";
run;
Finally, I use a SCAN function to read in one state at a time. I'm also getting an error here, but I think fixing the above part may solve it.
data x_MAIN_mod;
set x_MAIN;
array state(&count_states.) state:;
do i=1 to dim(state);
state(i) = scan(STATE,i,',');
end;
run;
Thanks in advance for the help!

Answer 1

Looks like you are almost there. Try this on the last Data Step.
data x_MAIN_mod;
set x_MAIN;
format out_state $2.;
nstate = countw(state,",");
do i=1 to nstate;
out_state = scan(state,i,",");
output;
end;
run;

Answer 2

Do you have to actually have two steps like that? You can use a 'big number' in a temporary variable and not have much effect on things, if you don't have the intermediate dataset.
data x_MAIN;
length state_temp $150;
set MAIN;
if STATE='ALL' then STATE_temp="&all_states.";
else STATE_temp=STATE;
array state(&count_states.) state:;
do i=1 to dim(state);
state(i) = scan(STATE,i,',');
end;
drop STATE_temp;
run;
If you actually do need the STATE, then honestly I'd go with the big number (=50*3, so not all that big) and then add OPTIONS COMPRESS=CHAR; which will (give or take) turn your CHAR fields into VARCHAR (at the cost of a tiny bit of CPU time, but usually far less than the disk read/write time saved).