topic Re: Basic Libname Macro Issue in SAS Programming

Basic Libname Macro Issue

cc1986 — Wed, 22 Mar 2017 15:24:46 GMT

Hi everyone,

I'm trying to make myself use macros more and have come up with an error in a basic macro that will assign a libname by year and file location. See below:

%macro yearc;

%let year= 2012 2013 2014 2015;

	%do i=1 %to 4;
		%let yearold=%scan(&year, &i);

			libname old&yearold '\\cdc.gov\project\CCID_NCIRD_DBD_MVPDB\Epi Team\Pertussis Epi\EIP\Enhanced Surveillance Project\Data\Formatted Data\Historic Datasets\Static_1999_&yearold_Dataset';

		%end;
	%mend yearc;
%yearc;

The macro revolves the first &yearold varible in the libname statement creating the libarary, but it doesn't work with the macro variable in the libname statement for the file pathway. It just resolves to C:\\My Documents\Old_Datasets\Finalized_1999_&yearold._Dataset. Am I missing something? Any suggestions would be much appreciated!

Thanks!

Re: Basic Libname Macro Issue

Kurt_Bremser — Wed, 22 Mar 2017 15:27:17 GMT

Macro triggers (% and &) are not resolved when enclosed in single quotes. Use double quotes instead.

Re: Basic Libname Macro Issue

ballardw — Wed, 22 Mar 2017 15:34:26 GMT

Macro variables do not resolve inside single quotes.

Use

libname old&yearold "\\cdc.gov\project\CCID_NCIRD_DBD_MVPDB\Epi Team\Pertussis Epi\EIP\Enhanced Surveillance Project\Data\Formatted Data\Historic Datasets\Static_1999_&yearold._Dataset";

Also when using a macro variable in a compound you need to have the dot operator to tell SAS to concatenate the following text.

&yearold_dataset would be considered the whole macro variable name.

See what result you get with:

%put &yearold_dataset;

to get familiar with the error message.

Also look at this and see that the scan, at least in your specific example is not needed.

%macro dummy;
%do YearOld = 2012 %to 2014;

	%put	libname old&yearold;

%end;
%mend dummy;
%dummy;

Re: Basic Libname Macro Issue

cc1986 — Wed, 22 Mar 2017 16:51:16 GMT

Hi,

Thank you both so much for your help! I guess I tried replacing the double-quotes and adding a period, but not at the same time. I will put this in my memory bank for the next macro I do. I'm slowly learning!

Thanks again,

cc1986

Re: Basic Libname Macro Issue

ballardw — Wed, 22 Mar 2017 17:04:07 GMT

A very helpful diagnostic with macros are the system options MPRINT SYMBOLGEN and MLOGIC.

They show the generated code, the resolution of macro variables and the results of macro logic (%if and similar) statements.

Options mprint symbolgen; /*turn on the option */

%macrocall

Options nomprint nosymbolgen; /* to turn off*/

Will provide a bit more information in the log to diagnose many issues.