在SQL Server中,我有一个包含以下字段的表。我想从每个组中获得前N行。我已尝试使用Rank()和Row_number()进行sql查询,但排名和行号不是按顺序排列,因此无法限制行。
这是我试过的SQL查询,正如你在结果中看到的那样,rank列没有序列号所以"其中"子句不适用于每组的前三行。
使用ROW_NUMBER(),DENSE_RANK()
观察到类似的结果 SELECT Rs.RunID,rs.SiteCode,procedure_name,rs.total_cpu_time, rank
FROM (
SELECT RunID, SiteCode,total_cpu_time, procedure_name, rank()
over (Partition BY sitecode
ORDER BY total_cpu_time desc ) AS Rank
FROM TopProcs
-- ) rs WHERE Rank between 1 and 15 and RunID = 1 and SiteCode in ('CAS', 'P01')
) rs WHERE RunID = 1 and SiteCode in ('CAS', 'P01')
order by SiteCode`
这是输出,
RunID SiteCode procedure_name total_cpu_time rank
1 CAS spDRSActivation 117039139161 1
1 CAS spDRSSendChangesForGroup 155827022 2
1 CAS spDRSMsgBuilderActivation 153595640 3
1 CAS spGetChangeNotifications 360607 30
1 CAS spDRSSendSyncComplete 100169 65
1 CAS spSendRcmServiceBrokerMessage 88270 67
1 CAS spLogEntry 53466 78
1 P01 spDRSMsgBuilderActivation 62843590384 9
1 P01 spDRSSendChangesForGroup 62746448352 10
1 P01 spDrsSummarizeSendHistory 54443397908 13
1 P01 CH_SummarizePolicyRequests 35371363957 18
1 P01 spProcessDCMComplianceMsg 29790879064 25
1 P01 spUpdateComplianceDetails 22106121907 26
答案 0 :(得分:3)
我假设您希望获得TOP N
分区的sitecode
结果,并total_cpu_time
作为订单。如果您需要在内部查询中过滤后过滤数据,则可以将Where
子句放在里面。
您可以使用Row_Number()
代替rank()
,
SELECT rs.RunID,rs.SiteCode,rs.procedure_name,rs.total_cpu_time, rn
FROM (
SELECT
RunID,
SiteCode,
total_cpu_time,
procedure_name,
Row_Number() OVER (PARTITION BY SiteCode ORDER BY total_cpu_time DESC) AS rn
FROM TopProcs
WHERE
RunID = 1
AND SiteCode IN('CAS', 'P01')
) rs
WHERE
rs.rn < 4
ORDER BY SiteCode
这将返回每个SiteCode的前3行。
答案 1 :(得分:0)
你可以使用DENSE_RANK:
SELECT Ranked.[SiteCode], Ranked.[procedure_name], Ranked.[total_cpu_time]
FROM (
SELECT [SiteCode], [procedure_name], [total_cpu_time], DENSE_RANK() OVER (PARTITION BY [SiteCode] ORDER BY [total_cpu_time] DESC) AS [Rank]
FROM #TopProcs
) Ranked
WHERE Ranked.[Rank] <= 3