Building a comma separated list?

Question

I\'m tryin to use SQL to build a comma separated list of cat_id\'s

the code is:

declare     @output varchar(max)
set         @output = null;
select @         


        

Answer 1

declare     @output varchar(max)

select      @output = coalesce
                      ( 
                          @output + ', ' + convert(varchar(max),cat_id), 
                          convert(varchar(max),cat_id)
                      )
from        yourTableHere

print       @output