unlang question

Something like if ("%{sqlnastype:SELECT Value from radcheck where UserName = '%{User-Name}' and otherconditions}" == 'bla' ) works, whereas I have problems with: if ("%{sqlnastype:SELECT Value from radcheck where UserName = '%{User-Name}' and other conditions.. " is not null ) Am I doing something wrong or is "is not null" not (yet) implemented? Norbert Wegener