SAS Selecting the most recent dataset in a lib automatically - sas

Question

i am working with a library that is updated every month or so, and i need a way to select the most recent dataset each month, i tried two methods that would show me the latest table, one that makes a table ordering from the modified date
proc sql;
create table tables as
select memname, modate
from dictionary.tables
where libname = 'SASHELP'
order by modate desc;
quit;
and one that gives me just the latest modified one
proc sql;
select memname into> latest_dataset
from dictionary.tables
where libname='WORK'
having crdate=max(crate);
%put &=latest_dataset;
and i would like to put these latest datasets in a table, but i don't know how, or if there is another easier way to do this, i am still very much new to SAS programming so i'm lost, any help is appreciated.

Answer 1

Use Proc APPEND to put the latest data set into a table. You are essentially accumulating rows.
Use SQL :INTO to obtain (place into a macro variable) the libname.memname of the data set that should be appended.
Example:
The task of determining the newest data set and appending it to a base table is also in a macro so the the code can be easily rerun in the example.
%macro append_newest;
%local newest_table;
proc sql noprint;
select catx('.', libname, memname) into :newest_table
from dictionary.tables
where libname = 'WORK'
and memtype = 'DATA'
having crdate = max(crdate);
%put NOTE: &=newest_table;
create view newest_view as
select "&newest_table" as row_source length=41, *
from &newest_table
;
proc append base=work.master data=newest_view;
run;
%mend;
* create an empty for accumulating new observations;
data work.master;
length row_source $41;
set one (obs=0);
run;
data work.one;
set sashelp.class;
where name between 'A' and 'E';
%append_newest;
data work.two;
set sashelp.class;
where name between 'Q' and 'ZZ';
%append_newest;
data work.three;
set sashelp.class;
where name between 'E' and 'Q';
%append_newest;
Will produce this master table that accumulates the little pieces that come in day by day.
You would want additional constraints such as a unique key in order to prevent appending the same data more than once.