10-06-2017 10:39 AM
I have the following code that generates an error. I am checking the matrix 'have' for the variable 'cusum'. If 'cusum' exists it is removed. The error I get is:
ERROR 117-185: There was 1 unclosed DO block.
data _null_; dsid=open('have'); check=varnum(dsid,'cusum'); if check=1 then do; data have(drop=cusum); set have; run; end; run;
10-06-2017 10:49 AM - edited 10-06-2017 10:51 AM
You can't have a data step inside a data step. That is the cause of the ERROR message you are seeing.
A better way to check to see if a variable exists and then delete it would be:
Use PROC SQL to query the DICTIONARY.COLUMNS table to see if the variable exists; and if it exists, then use PROC DATASETS to remove the variable from the data set. This would have to be done in a macro.
I'm curious as to why you need to conditionally delete a variable if it exists, as normally leaving an unwanted variable in a data set causes no problems other than taking up slightly more disk space.
10-06-2017 11:52 AM
Something like the below - although I totally agree with @PaigeMiller, there is rarely a need to delete a variable if you don't know about it up front, sounds like a lack of knowledge about your data.
data _null_; set sashelp.vcolumn (where=(libname="WORK" and memname="HAVE" and name="CUSUM")); call execute('data work.have; set work.have (drop=cusum); run;'); run;
10-06-2017 12:09 PM - edited 10-06-2017 12:11 PM
You don't actually need to check for the existence of the variable.
The system option DKRICOND determines whether or not and error is generated when you drop/keep/rename a variable that doesn't exist. It's default is DKRICOND=ERROR, but you can set it to NOWARN.
data have1; x=1; run; data have2; x=2; cusum=1; run; options dkricond=error; data want; set have1(drop=cusum) /*causes error cuz cusum does not exist*/ have2(drop=cusum) ; put _all_; run; options dkricond=nowarn; data want; set have1(drop=cusum) /*no error cuz DKRICOND=NOWARN*/ have2(drop=cusum) ; put _all_; run; options dkricond=error; *restore the default;