Query to select individual records similar to distinct

Question

The below query must return only one record for a account and not all the records. Additional columns cannot be added to the select statement.
SELECT a.CODE, a.AMOUNT,a.DATEtime
FROM PAYMENTS a,SB b
WHERE a.TYPE = 'X'
AND A.CODE=B.CODE
AND A.ACCT=B.ACCT
this is the sample output.
123     5000     01/01/2005
123     4500     01/01/2005 (Not required to display)
458     74100     01/01/2005
748     4744     01/01/2005
411     4588     01/01/2005
411     7488     01/01/2005 (Not required to display)
thanks in advance for your help.

Answer 1

Hi,
Satya's Query didn't work because only ROW_NUMBER was misspelled.
SQL> ed
Wrote file afiedt.buf
  1  WITH T as (SELECT 123 Code, 5000 Amount, '01/01/2005' DateTime FROM DUAL UNION ALL
  2  SELECT 123, 4500, '01/01/2005'  FROM DUAL UNION ALL
  3  SELECT 458, 74100, '01/01/2005'  FROM DUAL UNION ALL
  4  SELECT 748, 4744, '01/01/2005'  FROM DUAL UNION ALL
  5  SELECT 411, 4588, '01/01/2005'  FROM DUAL UNION ALL
  6  SELECT 411, 7488, '01/01/2005'  FROM DUAL)
  7  SELECT * FROM (
  8  SELECT Code,Amount,DateTime, ROW_NUMBER() OVER( PARTITION BY Code ORDER BY Code) RN FROM t)
  9* WHERE RN = 1
SQL> /
      CODE     AMOUNT DATETIME           RN
       123       5000 01/01/2005          1
       411       4588 01/01/2005          1
       458      74100 01/01/2005          1
       748       4744 01/01/2005          1
SQL>Regards