Trouble constructing query...

Question

The following is my data...
Oracle: 10/2G
WITH xTable AS (
                SELECT 2010 AS YEAR, 1 AS SEQ, 'JOHN'  AS NAME, 1110 AS ID fROM DUAL UNION ALL
                SELECT 2010 AS YEAR, 2 AS SEQ, 'JOHN'  AS NAME, 1110 AS ID FROM DUAL UNION ALL
                SELECT 2010 AS YEAR, 1 AS SEQ, 'BOB'   AS NAME, 1112 AS ID FROM DUAL UNION ALL
                SELECT 2010 AS YEAR, 1 AS SEQ, 'TERRY' AS NAME, 1114 AS ID FROM DUAL UNION ALL
                SELECT 2010 AS YEAR, 1  AS SEQ, 'CARL'  AS NAME, 1115 AS ID  FROM DUAL UNION ALL
                SELECT 2010 AS YEAR, 2  AS SEQ, 'CARL'   AS NAME, 1115 AS ID FROM DUAL UNION ALL
                SELECT 2010 AS YEAR, 3  AS SEQ, 'CARL' AS NAME, 1115 AS ID FROM DUAL UNION ALL
                SELECT 2009 AS YEAR, 1 AS SEQ, 'JOHN'  AS NAME, 1110 AS ID FROM DUAL UNION ALL
                SELECT 2009 AS YEAR, 1 AS SEQ, 'BOB'   AS NAME, 1112 AS ID FROM DUAL UNION ALL
                SELECT 2009 AS YEAR, 2 AS SEQ, 'BOB' AS NAME, 1112 AS ID FROM DUAL
SELECT YEAR,SEQ,NAME,ID, count(seq) over (partition by name, year) as seq_cnt
FROM   xTable
ORDER BY YEAR, NAMECurrent Output:
        YEAR     SEQ     NAME     ID     SEQ_CNT
1     2009     1     BOB     1112     2
2     2009     2     BOB     1112     2
3     2009     1     JOHN     1110     1
4     2010     1     BOB     1112     1
5     2010     1     CARL     1115     3
6     2010     3     CARL     1115     3
7     2010     2     CARL     1115     3
8     2010     1     JOHN     1110     2
9     2010     2     JOHN     1110     2
10     2010     1     TERRY     1114     1What i'm trying to do is to only pull back the max sequence(seq) for id's where there is more than one record for a specific year. So, I would like the output to be as following...
Desired Output:
        YEAR     SEQ     NAME     ID     
     2009     2     BOB     1112     
     2009     1     JOHN     1110     
     2010     1     BOB     1112     
     2010     3     CARL     1115     
     2010     2     JOHN     1110     
     2010     1     TERRY     1114      I'm not entirely sure how to go about this, so, any help would be appreciated.

Answer 1

you can try:
SELECT   YEAR, seq, NAME, ID
    FROM (SELECT a.*,
                 ROW_NUMBER() OVER(PARTITION BY YEAR, NAME ORDER BY seq DESC)
                                                                             rn
            FROM xtable a)
   WHERE rn = 1
ORDER BY YEAR, NAME;