declare
val number;
res number;
begin
val := -10;
select decode(sign(val),0,'',val) into res from dual;
dbms_output.put_line(res);
end;
val number;
res number;
begin
val := -10;
select decode(sign(val),0,'',val) into res from dual;
dbms_output.put_line(res);
end;