SAS Error trying to loop through multiple datasets - date

Question

I'm trying to run some code which will hopefully concatenate multiple months or years worth of data. I am trying to figure out when a field was populated with a value. I.e. there is field XYZ in my data set and it is populated with value A in November 2016. If I run my code from Jan - Dec I would like a new field populated with the date that SAS encounters a non-blank value in that field.
Here's my code:
options mprint symbolgen source mlogic merror syntaxcheck ;
%macro append_monthly(iStart_date=, iEnd_date=);
%local tmp_date i;
%let tmp_date = %sysfunc(intnx(month,&iStart_date,0,beginning)) ;
%do %while (&tmp_date le &iEnd_date);
%let i = %sysfunc(sum(&tmp_date),yymmn4.);
%put &i.;
%let tmp_date = %sysfunc(intnx(month,&tmp_date,1,beginning)) ;
libname note "my.qualifiers.fords.note&i." disp=shr;
data new ;
set note.file ;
%if ln_note_crbur_date_delinq ne '' %then spc_cmt_date = &i.;
run;
%end;
%mend;
%append_monthly(iStart_date=%sysfunc(mdy(5,1,2016)), iEnd_date=%sysfunc(mdy(10,1,2016)) );
LIBNAME _ALL_ CLEAR;
Here's a sample from log with errors :
SYMBOLGEN: Macro variable TMP_DATE resolves to 20606
SYMBOLGEN: Macro variable IEND_DATE resolves to 20728
MLOGIC(APPEND_MONTHLY): %DO %WHILE(&tmp_date le &iEnd_date) condition is TRUE; loop will iterate again.
MLOGIC(APPEND_MONTHLY): %LET (variable name is I)
SYMBOLGEN: Macro variable TMP_DATE resolves to 20606
MLOGIC(APPEND_MONTHLY): %PUT &i.
SYMBOLGEN: Macro variable I resolves to 1606
1606
MLOGIC(APPEND_MONTHLY): %LET (variable name is TMP_DATE)
SYMBOLGEN: Macro variable TMP_DATE resolves to 20606
MPRINT(APPEND_MONTHLY): spc_cmt_date = 1605 run;
SYMBOLGEN: Macro variable I resolves to 1606
MPRINT(APPEND_MONTHLY): libname note "my.qualifiers.fords.note1606" disp=shr;
ERROR: Unable to clear or re-assign the library NOTE because it is still in use.
ERROR: Error in the LIBNAME statement.
NOTE: The SAS System stopped processing this step because of errors.
WARNING: The data set WORK.NEW may be incomplete. When this step was stopped there were 0 observations and 622 variables.
WARNING: Data set WORK.NEW was not replaced because this step was stopped.
NOTE: The DATA statement used 0.01 CPU seconds and 49483K.
NOTE: The address space has used a maximum of 4292K below the line and 240388K above the line.
I can't figure out why this isn't working. Maybe this could work using Proc append.
Basically, I just want my output with a field that returns a date in the form of YYMM for when field ln_note_crbur_date_delinq was non-blank.
Any help would be greatly appreciated

Answer 1

I'd guess the reason for your error is that the handle is not being cleared on your source file before the next libname statement tries to re-assign.
An easy fix would be to use a different alias (libref) each time, as follows:
libname note&i "my.qualifiers.fords.note&i." disp=shr;
Then adjust your data step like so:
data new ;
set note&i..file ;
The next part appears to be confusion between macro logic and data step. Simply remove the % symbols as follows:
if ln_note_crbur_date_delinq ne '' then spc_cmt_date = &i.;
Finally, add a proc append before the %end as follows:
proc append base=work.final data=new; run;
If work.final does not exist, it will be created in the same format as new.
EDIT:
following discussion in comments, here is a revised approach:
%macro append_monthly(iStart_date=, iEnd_date=);
%local tmp_date i set_statement;
%let tmp_date = %sysfunc(intnx(month,&iStart_date,0,beginning)) ;
%do %while (&tmp_date le &iEnd_date);
%let i = %sysfunc(sum(&tmp_date),yymmn4.);
%let tmp_date = %sysfunc(intnx(month,&tmp_date,1,beginning)) ;
%let set_statement=&set_statement &i..file;
libname note&i "my.qualifiers.fords.note&i." disp=shr;
%end;
data new ;
set &set_statement;
if ln_note_crbur_date_delinq ne '' then spc_cmt_date = &i.;
run;
%mend;
%append_monthly(iStart_date=%sysfunc(mdy(5,1,2016)), iEnd_date=%sysfunc(mdy(10,1,2016)) );
LIBNAME _ALL_ CLEAR;