Getting distinct values with the highest value in a specific column - sql

Question

How can I get the highlighted rows from the table below in SQL? (Distinct rows based on User name with the highest Version are highlighted)
In case you need plain text table:
+----+-----------+---+
| 1 | John | 1 |
+----+-----------+---+
| 2 | Brad | 1 |
+----+-----------+---+
| 3 | Brad | 3 |
+----+-----------+---+
| 4 | Brad | 2 |
+----+-----------+---+
| 5 | Jenny | 1 |
+----+-----------+---+
| 6 | Jenny | 2 |
+----+-----------+---+
| 7 | Nick | 4 |
+----+-----------+---+
| 8 | Nick | 1 |
+----+-----------+---+
| 9 | Nick | 3 |
+----+-----------+---+
| 10 | Nick | 2 |
+----+-----------+---+
| 11 | Chris | 1 |
+----+-----------+---+
| 12 | Nicole | 2 |
+----+-----------+---+
| 13 | Nicole | 1 |
+----+-----------+---+
| 14 | James | 1 |
+----+-----------+---+
| 15 | Christine | 1 |
+----+-----------+---+
What I have so far is (works for one user)
SELECT USER, VERSION
FROM TABLE
WHERE USER = 'Brad'
AND VERSION = (SELECT MAX(VERSION ) FROM TABLE WHERE USER= 'Brad')

Answer 1

SELECT USER, max(VERSION) VERSION
FROM TABLE GROUP BY USER;
If you need an ID then
SELECT ID, USER, VERSION FROM (
SELECT ID, USER, VERSION,
RANK() OVER(PARTITION BY USER ORDER BY VERSION DESC) RNK
FROM TABLE
) WHERE RNK = 1;
if you have
| 2 | Brad | 5 |
+----+-----------+---+
| 3 | Brad | 3 |
+----+-----------+---+
| 4 | Brad | 5 |
The query with RANK gives you both users
| 2 | Brad | 5 |
+----+-----------+---+
| 4 | Brad | 5 |
If you need only one row then replace RANK() with ROW_NUMBER()
In your query you're using AND VERSION = (SELECT MAX(VERSION ) FROM TABLE WHERE USER= 'Brad') which is equivalent to RANK() (all rows with the max VERSION)

Answer 2

The first_value analytic function should do the trick:
SELECT DISTINCT FIRST_VALUE (id)
OVER (PARTITION BY name ORDER BY version DESC)
name,
FIRST_VALUE (version)
OVER (PARTITION BY name ORDER BY version DESC)
FROM my_table
Another way to go would be to use the row_number function:
SELECT id, name, version
FROM (SELECT id, name, version
ROW_NUMBER() OVER (PARTITION BY name ORDER BY version DESC) rn
FROM my_table)
WHERE rn = 1
Not sure which I prefer, personally. They each have their merit and their ugliness.

Answer 3

this might help you :
select id, user, version
from
(
select id, user, version, row_number() over (partition by user order by version desc) rownum
from yourtable
) as t
where t.rownum = 1
sql fiddle