@Astounding wrote: You have an extra "where" in your code. Seems like @Astounding has pinpointed the problem (there may be others).   Advice to @dwights: this difficulty can be prevented when you write macros by first writing code WITHOUT MACROS and WITHOUT MACRO VARIABLES for at least one iteration of your code and getting this code to work properly. This is highly recommended and prevents a lot of problems, and would have identified this double WHERE command problem immediately.  ... View more

Do you mean something like the following:   proc sql noprint; select name into :name_list separated by ' ' from sashelp.class ; quit; %let extra_name = ZZZ; %let name_list = &name_list &extra_name; %put name_list = &name_list;   Amir. ... View more

@dwights wrote: The varlist contains list of all column names of a table (got the list using proc contents) . CLSTR_NM is a column of that table which satisfies the if condition(which is a t-test result being significant) . What I'm trying to do in the code is get the list of all columns which are statistically significant when compared from two tables. Thanks! So show the code how you actually derived that list. And possibly more important at this point since you keep getting append errors: Code for how you build the BASE dataset you are using in the Proc Append code. ... View more