topic Re: Conditionally assign a library? in SAS Programming

Conditionally assign a library?

MrsC — Wed, 22 Jul 2020 16:45:04 GMT

Is there a way to conditionally assign a library? I have an EG project (egp file) with a prompt, and I want the user to pick which of 4 databases they want to connect to. If they pick 2, then I only want to invoke the libname statements for the 2 they selected. I have 4 macro variables that indicate whether they want the library assigned or not.

It is not working to put the libname statement in a select or an if-then-else because it gets invoked regardless.

Re: Conditionally assign a library?

smantha — Wed, 22 Jul 2020 16:46:16 GMT

Can you show some code. If mac variables are mac1 , mac2, mac3 and mac4 and they have a boolean of YES or NO you can do the following

%macro assign_libname;
%if &mac1 = YES %then %do;
data _NULL_;
call execute(<libname statement 1>);
run;
%end;
%if &mac1 = YES %then %do;
data _NULL_;
call execute(<libname statement 1>);
run;
%end;
%if &mac2 = YES %then %do;
data _NULL_;
call execute(<libname statement 2>);
run;
%end;
%if &mac3 = YES %then %do;
data _NULL_;
call execute(<libname statement 3>);
run;
%end;
%if &mac4 = YES %then %do;
data _NULL_;
call execute(<libname statement 4>);
run;
%end;
%mend assign_libname;
%assign_libname;

my guess is libname in open code is compile time statement and hence you see the behavior.

Re: Conditionally assign a library?

Reeza — Wed, 22 Jul 2020 16:48:10 GMT

Use the libname function.

data _null_;

if "&mac1" = "Y" then libname(name, path);
if "&mac2" = "Y" then libname(......);
if "&mac3" = "Y" then libname(......);
if "&mac4" = "Y" then libname(......);

run;

@MrsC wrote:

Is there a way to conditionally assign a library? I have an EG project (egp file) with a prompt, and I want the user to pick which of 4 databases they want to connect to. If they pick 2, then I only want to invoke the libname statements for the 2 they selected. I have 4 macro variables that indicate whether they want the library assigned or not.

It is not working to put the libname statement in a select or an if-then-else because it gets invoked regardless.

Re: Conditionally assign a library?

smantha — Wed, 22 Jul 2020 16:54:38 GMT

did not think of libname function.

Re: Conditionally assign a library?

Reeza — Wed, 22 Jul 2020 16:57:55 GMT

I likely have the benefit of seeing this problem before 🙂

Re: Conditionally assign a library?

MrsC — Wed, 22 Jul 2020 17:49:09 GMT

CALL EXECUTE! Of course! Thank you so much.

Re: Conditionally assign a library?

smantha — Wed, 22 Jul 2020 18:33:31 GMT

I find @Reeza Solution much elegant than what I provided.