我有这样一张桌子（claimTable），
Time Terminal_ID Claims data_from
------------------------------------------------
2017-10-19 06:03:00 1 561 2
2017-10-19 06:04:00 1 562 2
2017-10-19 06:05:00 1 562.3 2
2017-10-19 06:06:00 1 563 2
2017-10-19 06:03:00 9 471 2
2017-10-19 06:04:00 9 471.9 2
2017-10-19 06:05:00 9 472.3 2
2017-10-19 06:06:00 9 473 2
2017-10-19 06:07:00 1 567 1
2017-10-19 06:08:00 1 567.6 1
2017-10-19 06:09:00 1 568.2 1
2017-10-19 06:10:00 1 569 1
2017-10-19 06:07:00 9 475 1
2017-10-19 06:08:00 9 475.9 1
2017-10-19 06:09:00 9 476.3 1
2017-10-19 06:10:00 9 476.3 1
每个ID都有数天的数据。我只在上面显示了一些数据。现在，我从Terminal_ID = 1检查每个data_from的最旧数据，
select min(Time), Terminal_ID
from claimsTable
where data_from = 1
group by Terminal_ID
我为每个ID获得2017-10-19 06:07:00。
接下来，我会检查Terminal_ID = 2中每个data_from的最新数据，
select max(Time), Terminal_ID
from claimsTable
where data_from = 2
group by Terminal_ID
现在，我为每个2017-10-19 06:06:00获得Terminal_ID。
现在，我希望从最新时间（最大（TIME）data_from = 2）获得60分钟的数据来计算每小时的平均值，该平均值来自{{1}的最旧数据} = 1.
所以，我使用像这样的自联接进行了检查，
data_from这不会给我所需的检查，因为我没有在select
t1.[Time], t1. Terminal_ID
from
claimsTable t1
inner join
claimsTable t2
on t1.Terminal_ID = t2. Terminal_ID
where t1. Terminal_ID = t2. Terminal_ID and
t1.[Time] between dateadd(mi,-59,t2.[Time]) and t1.[Time]
中使用max和t2函数min。当我自我加入时，我不确定如何包含它们。
我的预期输出表：
t1如何检查Time Terminal_ID Claims data_from
------------------------------------------------
2017-10-19 06:03:00 1 561 2
2017-10-19 06:04:00 1 562 2
2017-10-19 06:05:00 1 562.3 2
2017-10-19 06:06:00 1 563 2
2017-10-19 06:07:00 1 567 1
2017-10-19 06:03:00 9 471 2
2017-10-19 06:04:00 9 471.9 2
2017-10-19 06:05:00 9 472.3 2
2017-10-19 06:06:00 9 473 2
2017-10-19 06:07:00 9 475 1
= 2中之前60分钟的数据，从data_from = 1开始查找最旧的数据？
答案 0 :(得分：1)
我试图计算Avg和mintime(data_from = 1 )之间所有记录的(Max - 60 mins AND data_from == 2)
问题是我得到NULL这两种情况可能是因为查询中缺少某些内容 - 或者数据不够
尝试运行查询，如果有任何问题让我知道。
这是查询创建样本数据的查询：
-- CREATE SAMPLE DATA
DROP TABLE #claimsTable
CREATE TABLE #claimsTable
(
[Time] DateTime,
Terminal_ID INT,
Claims FLOAT,
data_from INT
)
INSERT INTO #claimsTable
VALUES
(N'2017-10-19 06:03:00', 1 , 561 , 2),
(N'2017-10-19 06:04:00', 1 , 562 , 2),
(N'2017-10-19 06:05:00', 1 , 562.3, 2),
(N'2017-10-19 06:06:00', 1 , 563 , 2),
(N'2017-10-19 06:03:00', 9 , 471 , 2),
(N'2017-10-19 06:04:00', 9 , 471.9, 2),
(N'2017-10-19 06:05:00', 9 , 472.3, 2),
(N'2017-10-19 06:09:00', 9 , 473 , 2),
(N'2017-10-19 06:07:00', 1 , 567 , 1),
(N'2017-10-19 06:08:00', 1 , 567.6, 1),
(N'2017-10-19 06:09:00', 1 , 568.2, 1),
(N'2017-10-19 06:10:00', 1 , 569 , 1),
(N'2017-10-19 06:05:00', 9 , 475 , 1),
(N'2017-10-19 06:08:00', 9 , 475.9, 1),
(N'2017-10-19 06:09:00', 9 , 476.3, 1)
我在示例数据中更改了1到2次，以便更好地理解我的查询生成的结果
实际查询从这里开始：
Select
A.TerminalId,
Avrg = AVG(data_between.Claims)
From
(
-- this inner query returns
/*
TerminalId | MaxTime (data_from == 2) | Min Time (data_from == 1)
-------------------------------------------------------------------------------------
9 | 2017-10-19 06:09:00.000 | 2017-10-19 06:05:00.000
1 | 2017-10-19 06:06:00.000 | 2017-10-19 06:07:00.000
*/
Select
TerminalId = data_from_2.Terminal_ID,
MaxTime2 = MAX(data_from_2.[Time]),
MinTime1 = data_from_1.[Time]
From
#claimsTable data_from_2
-- This will get MIN the data_from = 1 for each terminal_id
CROSS APPLY (
SELECT TOP (1)
*
FROM #claimsTable a
WHERE a.data_from = 1 AND a.Terminal_ID = data_from_2.Terminal_ID
ORDER BY a.[Time] ASC
) data_from_1
--
Where data_from_2.data_from = 2
-- group by to get the Max.Time for each terminal
GROUP BY data_from_2.Terminal_ID, data_from_1.[Time]
) A
-- join with claimsTable again to get the data between mintime(data_from = 1 ) and (Max - 60 mins) so we can calculate avg
LEFT JOIN #claimsTable data_between on data_between.Terminal_ID = A.TerminalId AND data_between.[Time] BETWEEN A.MinTime1 AND DATEADD(MINUTE, -60, A.MaxTime2)
--
GROUP BY A.TerminalId
答案 1 :(得分：0)
只需在自联接的时间列上使用max函数。
select
max(t2.[Time]),
t1.Terminal_ID
from
claimsTable t1
full join
claimsTable t2
on t1.Terminal_ID = t2. Terminal_ID
and t2.time <= dateadd(mi,-59,t1.[Time])
group by
t1. Terminal_ID