SQL Server : select latest time - sql-server

Question

I have a query that works well but has one problem, it displays other data I don't want.
The data is the latest of each username.
Here is the query:
SELECT
l.USER_KEY AS id,
l.USER_ID AS username,
gl1.CHAR_KEY AS char_id,
gl1.NAME AS charname,
gl1.GATENUM AS server,
CONVERT(VARCHAR(20), l.LOGINTIME, 100) AS user_time,
CONVERT(VARCHAR(20), gl1.OCCUR_TIME, 100) AS char_time
FROM LOG_CONNECT201211 AS gl1
JOIN game.dbo.CHAR_INFOR AS g --character data
ON gl1.CHAR_KEY = g.CHAR0_KEY OR gl1.CHAR_KEY = g.CHAR1_KEY OR gl1.CHAR_KEY = g.CHAR2_KEY
JOIN login.dbo.USER_CHECK_LOGIN AS l --login data
ON g.USER_KEY = l.USER_KEY
JOIN (SELECT char_key, max(OCCUR_TIME) as mostrecent --game logs
FROM LOG_CONNECT201211
WHERE KIND=20 OR KIND=21
GROUP BY char_key) AS gl2
ON gl2.char_key = gl1.char_key and gl2.mostrecent = gl1.OCCUR_TIME
WHERE l.CHECKLOGIN = 1
ORDER BY username DESC
That returns:
id username char_id name map user_time char_time
------------------------------------------------------------------------------------
3667 zr5970 11002 warpath 4 Nov 15 2012 8:54AM Nov 7 2012 6:31AM
3667 zr5970 11004 bloodfines 4 Nov 15 2012 8:54AM Nov 7 2012 6:33AM
3667 zr5970 11003 hanzhou 1 Nov 15 2012 8:54AM Nov 15 2012 8:54AM
14999 yvacosta 52086 Creams 1 Nov 15 2012 8:17AM Nov 15 2012 8:17AM
23433 yurich 1911481 abal 5 Nov 15 2012 8:34AM Nov 9 2012 4:05PM
23433 yurich 1911482 yurich 5 Nov 15 2012 8:34AM Nov 15 2012 8:30AM
23433 yurich 1911483 sharmaine 5 Nov 15 2012 8:34AM Nov 15 2012 8:35AM
10967 yubiwamoi 33376 Dwina 1 Nov 15 2012 4:33AM Nov 15 2012 4:33AM
So the data is correct, but I only want to return one row per username.
On this data the username returns 3, with 3 names, but the only name I want is that one with the latest char_time.
Example correct data:
id username char_id name map user_time char_time
-----------------------------------------------------------------------------------
3667 zr5970 11003 hanzhou 1 Nov 15 2012 8:54AM Nov 15 2012 8:54AM
14999 yvacosta 52086 Creams 1 Nov 15 2012 8:17AM Nov 15 2012 8:17AM
23433 yurich 1911483 sharmaine 5 Nov 15 2012 8:34AM Nov 15 2012 8:35AM
10967 yubiwamoi 33376 Dwina 1 Nov 15 2012 4:33AM Nov 15 2012 4:33AM
Notice that I only displayed the data for zr5970 with the latest char_time
Please advice, Thank you.

Answer 1

Use ROW_NUMBER()
SELECT *
FROM
(
SELECT
l.USER_KEY AS id,
l.USER_ID AS username,
gl1.CHAR_KEY AS char_id,
gl1.NAME AS charname,
gl1.GATENUM AS server,
CONVERT(VARCHAR(20), l.LOGINTIME, 100) AS user_time,
CONVERT(VARCHAR(20), gl1.OCCUR_TIME, 100) AS char_time,
rn = row_number() over (partition by l.USER_KEY order by gl1.OCCUR_TIME DESC)
FROM LOG_CONNECT201211 AS gl1
JOIN game.dbo.CHAR_INFOR AS g --character data
ON gl1.CHAR_KEY = g.CHAR0_KEY OR gl1.CHAR_KEY = g.CHAR1_KEY OR gl1.CHAR_KEY = g.CHAR2_KEY
JOIN login.dbo.USER_CHECK_LOGIN AS l --login data
ON g.USER_KEY = l.USER_KEY
WHERE l.CHECKLOGIN = 1
) X
WHERE rn=1
ORDER BY username DESC

Answer 2

First select just the user name and the max time. This way you will have the correct number of rows. When you have that you can easily the other columns to your query...

Answer 3

select a.USER_KEY AS id,
l.USER_ID AS username,
gl1.CHAR_KEY AS char_id,
gl1.NAME AS charname,
gl1.GATENUM AS server,
CONVERT(VARCHAR(20), l.LOGINTIME, 100) AS user_time,
CONVERT(VARCHAR(20), gl1.OCCUR_TIME, 100) AS char_time
from
(select user_key, max(occur_time) as mostrecent
from log_connect2011
WHERE KIND=20 OR KIND=21
group by user_key) a
join LOG_CONNECT201211 AS gl1 on a.user_key = gl1.user_key and a.mostrecent = gl1.occur_time
JOIN game.dbo.CHAR_INFOR AS g --character data
ON gl1.CHAR_KEY = g.CHAR0_KEY OR gl1.CHAR_KEY = g.CHAR1_KEY OR gl1.CHAR_KEY = g.CHAR2_KEY
JOIN login.dbo.USER_CHECK_LOGIN AS l --login data
ON g.USER_KEY = l.USER_KEY
WHERE l.CHECKLOGIN = 1
ORDER BY username DESC