I suppose symexist is used for checking macro variables (local ones). I made a test but the output is out of my expectation. The code is:
%macro test(t1,t2);
%if %symexist(t1) %then %put &t1. is exist;
%if %symexist(t2) %then %put &t2. is exist;
%mend;
%test(test1,);
The output is:
test1 is exist
is exist
Looking at the mlogic: %IF condition %symexist(t2) is TRUE.
There is no macro variable for t2. How it comes for TRUE? Anyone come explain how symexist works? I had a search but did not find.
Thanks,
Andrea
There are macro variables named T1 and T2 because you defined them by making them parameters to your macro. All macro parameters are local macro variables to the macro.
You need to use &t1 not t1 because you want to test for the existence of test1 not the existence of t1.
It will still error out though, because the macro variable t2 doesn't exist.
%let test1 = Yes;
%macro test(t1, t2);
%if %symexist(&t1) %then
%put &t1. is exist;
%if %symexist(&t2) %then
%put &t2. is exist;
%else
%put &t2. does not exist;
%mend;
%test(test1, test2);
The output will be:
test1 is exist
test2 does not exist
Related
I am trying to solve a problem in which, based on certain conditions, it assigns you a parameter with the let function. For this exercise I am using %if with %let conditions on the code. The code I have written so far in simplified way is the following:
%let anio = 2022;
%let base = 2;
%Macro Data;
%if &anio = 2022 %then %do;
%Let year_add = %Str(&Base.C);
%Let year_add1 = %Str(&Base.B);
%mend;
%Data;
%put &=year_add;
%put &=year_add1;
The problem is that apparently the macro is not assigning any value to me in the second let statement
The first %put = &year_add gives me the correct result 2C.
Unfortunately with the second %put = &year_add1 it appears the following message: apparent symbolic referenc yeard_add1 not resolved
Can anyone can give me a hand or advise on how I can assign different let statements based on a condition?
Thanks in advance.
Your macro definition is missing an %END for the %DO.
%macro data;
%if &anio = 2022 %then %do;
%let year_add = &Base.C;
%let year_add1 = &Base.B;
%end;
%mend;
If the target macro variables, YEAR_ADD and YEAR_ADD1 do not already exist then your macro will create them as LOCAL to the DATA macro. So once the macro finishes they will be removed.
The easiest solution is just to make sure the macro variables exist before you call the macro.
%let anio = 2022;
%let base = 2;
%let year_add=;
%let year_add1=;
%data;
%put &=year_add;
%put &=year_add1;
If you are certain the macro variables do not already exist in some other macro that is calling %DATA() then you could add a %GLOBAL statement to define them in the GLOBAL macro scope so they will not be removed when the macro finishes by adding this to the macro definition:
%global year_add year_add1 ;
But that will generate an error if they have been defined as LOCAL to some other macro that called %DATA. So to be safe only force them into the GLOBAL scope if they do not already exist.
%if not %symexist(year_add) %then %global year_add;
%if not %symexist(year_add1) %then %global year_add1;
But the logic does not require you to define a macro. Just use the %IF/%THEN/%DO/%END block in open code. Then you won't have any macro variable scoping issues.
%if &anio = 2022 %then %do;
%let year_add = &Base.C;
%let year_add1 = &Base.B;
%end;
That works fine unless you are running on some really old version of SAS.
I am getting a generic 'Statement not valid or out of order' message with the below:
%macro test;
data _null_;
%if %sysfunc(fileexist("C:\report_201809.xlsx")) = 1 %then %do;
rc=%sysfunc(rename("C:\report_201809.xlsx",
"C:\report_201809.xlsx"_old.xlsx",'file'));
%end;
%mend;
%test;
The code below should get you what you need. While you can use %if statements in a data step you generally won't need to. I'm guessing the error is coming from the %sysfunc function around the fileexist and rename functions. %sysfunc allows you to call data step functions outside of a data step so it is not needed here.
%macro test;
data _null_;
if fileexist("C:\file.txt") then do;
rc = rename("C:\file.txt", "C:\file2.txt", 'file');
end;
run;
%mend;
Alternatively, you could use an X Command that allows you to execute Windows commands. You could replace the rename function with the following statement.
x move C:\file.txt C:\file2.txt;
Remove the DATA _NULL_ or proceed per #J_Lard.
Macro arguments used in %sysfunc invoked function calls are implicitly quoted and do not need additional ' or "
%macro test;
%local rc;
%if %sysfunc(fileexist(C:\report_201809.xlsx)) = 1 %then %do;
%let rc = %sysfunc(rename(C:\report_201809.xlsx,C:\report_201809_old.xlsx,file));
%end;
%test;
You original code may have worked (by way of non-obvious side effect) if the filename "C:\report_201809.xlsx"_old.xlsx" (having an extraneous ") was corrected to "C:\report_201809_old.xlsx"
I am new to SAS macro writing and I have been struggling with writing a code for the following instance.
%let DateOfInterest= "15jul2016"d;
%let yearyyyy=%sysfunc(putn(&DateOfInterest,year4.));
%let yearyyyy2=eval(yearyyyy+1);
data _null_;
if "01JAN2016"d<=&DateOfInterest<="31MAR2016"d then do;
%let reportdate="31MAR2016"d;
%let reportdate2="01APR2016"d;
%let reportdate3="01JAN2016"d;
%let QuarterOfInterest=Q1;
if "31MAR2016"d<&DateOfInterest<="30JUN2016"d then do;
%let reportdate="30JUN2016"d;
%let reportdate2="01JUL2016"d;
%let reportdate3="01APR2016"d;
%let QuarterOfInterest=Q2;
if "30JUN2016"d<&DateOfInterest<="30SEP2016"d then do;
%let reportdate="30SEP2016"d;
%let reportdate2="01OCT2016"d;
%let reportdate3="01JUL2016"d;
%let QuarterOfInterest=Q3;
if "30SEP2016"d<&DateOfInterest<="31DEC2016"d then do;
%let reportdate="31DEC2016"d;
%let reportdate2="01JAN2017"d;
%let reportdate3="01OCT2016"d;
%let QuarterOfInterest=Q4;
end;
end;
end;
end;
run;
The code runs without any problem. However, whatever DateOfInterest I choose, the reportdate variables come out to be the ones specified in the last if loop. is there a way to change the code in order to have reportdates variable in line with the DateOfInterest?
Thanks.
You're combining macro with data step in a way that doesn't work. Macro language and data step language are basically unrelated: macro language can write data step code, and the other way around, but not affect each other generally.
In particular, macro code is compiled and executed first, before any dataset is opened or any data step code is compiled or executed. That's the point really - it lets you write datastep code pre-compilation.
So
if ... then do;
%let something
end;
That doesn't work, because the macro %let happens first, then later the data step happens.
%if ... %then %do;
%let something
%end;
That works, because it's all in the macro language. Generally speaking, if it doesn't have a % at the start, it's not a macro statement/function, and won't work on the macro language.
What you're doing is going to have some more complications, though. You have to be in a macro to use %if, but you also have scoping issues.
So a general small macro like this would be:
%let mval=1;
%macro set_things;
%if &mval=1 %then %do;
%let mval1=1;
%end;
%else %if &mval=2 %then %do;
%let mval2=1;
%end;
%else %do;
%let mval0=1;
%end;
%mend;
%set_things();
%put &=mval &=mval0 &=mval1 &=mval2;
Notice that doesn't work: because it's not global, so you need one more line inside the macro:
%global mval0 mval1 mval2;
That tells SAS to make them available in the global area.
I am designing a generic macro to do update a table using a macro variable (say X) which is used as a column name. The problem I have is that there are ocassions where this variable X (which is used as a column name in the where clause) is null. Can someone help please
I you don't want a where clause when &X is blank, then do something like:
%if %length(&X) > 0 %then where &X = 'blahblah';
So that the where clause is only created if &X has text in it.
If &x is guaranteed to be defined but may be blank, then DWal's solution is the way to go. This is useful basically when the macro variable is a parameter, and will be defined every time the macro is run.
If it may not be defined at all, then you need to use %symexist() to check whether the macro variable is defined at all, possibly in addition to the %length check.
%macro test;
%if %symexist(X) %then %if %length(&x)>0 %then %do;
%put &=x;
%end;
%mend test;
%symdel x; *deletes x if it exists;
%test;
%let x=;
%test;
%let x=XValue;
%test;
I nest the %if to avoid an unintialized note.
I have simplified this a lot so it can be repeated
%macro macro_one(dt2);
%let var1 = &dt2;
%mend;
Then I have another macro and I want to use the output from macro one in macro 2
%macro macro_print(dt2);
/*call macro 1*/
%macro_one(&dt2);
%put &var1;
%mend;
/call macro/
%macro_print('purple');
It should print purple in the logs but I get an error
I get an error though - i suspect I need to assign the macro variable from macro one when I call macro two.
First, I suspect you have a typo between your code and here. Proper way to define a macro is:
%macro blah(x);
<do stuff>
%mend;
not:
%macro_blah(x);
<do stuff>
%mend;
The macro is created in %macro_one and defaults to a local scope. You can fix this by declaring it %global.
%macro macro_one(dt2);
%global var1;
%let var1=&dt2;
%mend;
Also, use %put not put in %macro_two.