Unique Column In Table

Hai all,


i am creating one table like CREATE TABLE XX( CODE NUMBER, NAME VARCHAR(10).

I AM INSERTING THE 5 RECORDS LIKE

OUTPUT IS
--------------

CODE NAME
1 A
2 B
3 C
4 D
2 A

problem is There is no unique column in that table.

is there any unique column in ACCESS. like

for Exp: in SQLBASE is ROWID is unique column.
in ORACLE is ROWNUM is unique column.


pls help

Thanks & Regards

Narasareddy