如何获得在SQL Server
问题描述:
SELECT RIGHT(timestamp,LEN(timestamp) -12) as DailyTime, left(roundtrip, LEN(roundtrip) -2) as HalfHourDuration, site_code
FROM tblServer_Status
WHERE timestamp >= dateadd(day, datediff(day,'19000101',CURRENT_TIMESTAMP),'19000101') AND timestamp < dateadd(day, datediff(day,'19000101',CURRENT_TIMESTAMP)+1,'19000101') AND server = 'ServerName' AND site_code = 'A'
GROUP BY timestamp, roundtrip, site_code HAVING(((COUNT(site_code))>0))
ORDER BY timestamp
每个时间间隔最新值我有这样的代码,让我这种输出如何获得在SQL Server
| DailyTime | HalfHourDuration | Site_Code|
12:00AM 122 A
12:00AM 143 A
12:00AM 242 A
12:30AM 112 A
12:30AM 222 A
12:30AM 462 A
01:00AM 322 A
01:00AM 642 A
01:00AM 322 A
01:30AM 146 A
01:30AM 167 A
01:30AM 116 A
02:00AM 163 A
02:00AM 145 A
02:00AM 121 A
02:30AM 149 A
02:30AM 135 A
02:30AM 111 A
...................................
,但我需要得到每一次最新的时间。 喜欢这个
| DailyTime | HalfHourDuration | Site_Code|
12:00AM 242 A
12:30AM 462 A
01:00AM 322 A
01:30AM 116 A
02:00AM 121 A
02:30AM 111 A
就是这样的。 任何人都可以帮助我配置我的代码。
谢谢。
答
可以使用row_number()
做到这一点:
with t as (
<your query here without order by>
)
select t.*
from (select t.*,
row_number() over (partition by DailyTime
order by HalfHourDuration desc
) as seqnum
from t
) t
where seqnum = 1;
伙计。谢谢。但时间的顺序是按数字。你能帮我把它按AM - PM排序。 – Elphrian
我需要从12:00 AM到11:30 PM的时间排序。感谢您的答复。 – Elphrian