SQL> select * from a;

NAME
----------
GP
GP
GP
*null*
*null*
JP
JP

7 rows selected.

SQL> select * from a order by name asc nulls first;

NAME
----------
*null*
*null*
GP
GP
GP
JP
JP

7 rows selected.


select name from a order by name asc nulls first;

NAME
----------
*null*
*null*
GP
GP
GP
JP
JP