Macro error

[robertrao]

Hi Tom,

I understansd that the below code sets

intext.final_all   and  intext.&itb_extb ;

could you explain the meaning of :

%if exist(intext.final_all) %then intext.final_all ;

Thanks

data intext.final_all ;

  set

%if exist(intext.final_all) %then intext.final_all ;

   intext.&itb_extb ;

run;

[Tom]

First there is a mistake in the code.  For it to work right as macro logic I needed to wrap the EXIST() function call in a %SYSFUNC() macro function call.

%if %sysfunc(exist(intext.final_all)) %then intext.final_all ;

What that statement means is that when the dataset INTEXT.FINAL_ALL exists the macro should generate the SAS code INTEXT.FINAL_ALL.  Since there is no %ELSE clause when the dataset does not exist then it generates no SAS code at all.  So the effect is that when the dataset exists both datasets are referenced in the SET statement and when it does not only the new data is referenced.