请教open() function

shiyiming

data b;
input x1 y;
cards;
1 20
2 50
;
run;
%macro aaa;
%let dsid=%sysfunc(open(b));
%if %sysfunc(varnum(&dsid.,x))^=0 %then %do;
data c;set b;
xy=x;
run;
%end;
%else %do;
data c;set b;
xy=y;
run;
%end;
%mend;
%aaa

如例所示，运行之后，便无法删除data b. log提示data b在使用中，这是怎么回事？
如果是open的原因,请问,在使用open的前提下,我该如何关闭,或如何去除这个情形(不能自由的建立或删除一个dataset)？
thanks a lot!

shiyiming

you have to close the dataset somewhere before the %mend;

        %let dsid=sysfunc(close(&dsid));

shiyiming

I tried, but failed for %let dsid=%sysfunc(close(&dsid));  .
even I tried  %let dsid=%sysfunc(close(b));, but still wrong;
could anyone give me a suggestion, thanks a lot.

shiyiming

Close your SAS, re-start it. open funcion and colse funcion must be used in pair.

shiyiming

yes, I tried again according what you suggested, cloase SAS and reopen it(repeat it hundreds times). then, run the code besides the line :
data b;
input x1 y;
cards;
1 20
2 50
;
run;
%macro aaa;
%let dsid=%sysfunc(open(b));
%if %sysfunc(varnum(&dsid.,x))^=0 %then %do;
data c;set b;
xy=x;
run;
%end;
%else %do;
data c;set b;
xy=y;
run;
%end;

%let dsid=%sysfunc(close(&dsid));
/*
%let dsid=sysfunc(close(&dsid)); or
%let dsid=%sysfunc(close(&dsid)); or
%let rc=%sysfunc(close(&dsid));
*/

%mend;
%aaa

however, nothing changed, and the problem still there.(BTW, what is your SAS? 9.1 or 9.2? Mine is 9.1.)
can anyone help? Thanks.

shiyiming

i restarted my PC&SAS and run the code, everything looks normal now, thanks a lot!!!

shiyiming

其实跟你用察看器打开数据集道理一样的，你要关上才行。

shiyiming

the correct way is to close the dataset before your next step to open it.
%macro aaa;
%let dsid=%sysfunc(open(b));
%if %sysfunc(varnum(&dsid.,x))^=0 %then %do;
%let dsid=%sysfunc(close(&dsid));
data c;set b;
xy=x;
run;
%end;
%else %do;
%let dsid=%sysfunc(close(&dsid));
data c;set b;
xy=y;
run;
%end;

%mend;
%aaa