Problem with or condition in if statement

Question

Dear Oracle experts,
I have a strange problem with Oracle 10g1R1 :
The script below should normally write the value 1, 2, 3, 4, 5, 7, 9, 10 into my table.
But itwrites all the values from 1 to 10 into my table.
Only if I use only one condition without the 'or' the
if condition is successful.
Is this a normal behaviour of the database ?
If yes, then why ?
Best regards,
Daniel Wetzler
create table messages (results varchar2(30));
declare
var1 number;
begin
for i in 1..10 loop
dbms_output.put_line(i);
if (i != 6) or (i != 8)
then
insert into messages results values (i);
end if;
end loop;
commit;
end;
/

Answer 1

You want to use AND for that condition, not OR
SQL> begin
  2  for i in 1..10 loop
  3     if (i != 6) and (i != 8)
  4     then
  5        dbms_output.put_line(i);
  6     end if;
  7  end loop;
  8  end;
  9  /
1
2
3
4
5
7
9
10