Only Return the latest issue of a document

Question

Hi all,
I am trying to work out a script to only return the latest issue of a document. In the example below if I was using the correct statement I would only return the issue 3 records (AAA and AAB)
I am not sure what syntax/operator to use, can anyone help me..
Document Issue
AAA 1
AAA 2
AAA 3
AAB 1
AAB 2
AAB 3
I have tried the group by expression and the MAX operator...... to no avail....

Answer 1

Is this what you need?
SQL> CREATE TABLE dt_test_docs (        doc_id varchar2(10),
  2                                                     ver number,
  3                                                     updated_by varchar2(10),
  4                                                     updated_timestamp timestamp
  5                                             )
  6  /
Table created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('ABC',1,'user1',systimestamp-3)
  3  /
1 row created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('ABC',2,'user2',systimestamp-2)
  3  /
1 row created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('ABC',3,'user2',systimestamp-1)
  3  /
1 row created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('ABC',4,'user3',systimestamp)
  3  /
1 row created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('DEF',1,'user3',systimestamp-3)
  3  /
1 row created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('DEF',2,'user3',systimestamp-2)
  3  /
1 row created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('DEF',3,'user2',systimestamp-1)
  3  /
1 row created.
SQL> INSERT INTO dt_test_docs
  2  VALUES('DEF',4,'user1',systimestamp)
  3  /
1 row created.
SQL>
SQL> SELECT
  2     doc_id,
  3     ver,
  4     updated_by,
  5     updated_timestamp,
  6     max_ver
  7  FROM
  8     (
  9     SELECT
10             doc_id,
11             ver,
12             updated_by,
13             updated_timestamp,
14             MAX(ver) OVER(PARTITION BY doc_id) max_ver
15     FROM
16             dt_test_docs
17     )
18  WHERE
19     max_ver = ver
20  /
DOC_ID            VER UPDATED_BY UPDATED_TIMESTAMP                                                      MAX_VER
ABC                 4 user3      06-SEP-06 05.31.19.242000 PM                                                 4
DEF                 4 user1      06-SEP-06 05.31.19.304000 PM                                                 4