SQL Server sum query every 06:30 AM - sql-server

Question

Really need some help: I have a SQL Server table like this :
And I want to do a query to count value everyday start from 06:30 today until 06:29 tomorrow.
The problem is, the value does not start from 0 every 06:30.
I need query like this: Select maximum value per code first, ex :
(code : value)
M12 : 108,
M77 : 26
then the M77 value not start from 06:30.
I need to do : 26 - 12 (value before 06:30:00), so the M77 now is 14.
Finally sum the M77 and M12 = 14 + 108 = 122.
My expected output only for total value per date.
Based on my DB (image), the total value will be 26 - 12 =14.
26 is the latest value.
12 is value before 06:30
How to do it in SQL Server? Please help me

Answer 1

if i do understand you requirement correctly.
The query explanation are in code comments
; with
-- for getting the max value by code, rn = 1 is the max value
cte1 as
(
select *, rn = row_number() over (partition by code order by value desc)
from sample_table
),
-- for getting rows before 6:30, rn = 1 is the last record before 6:30
cte2 as
(
select *, rn = row_number() over (partition by code order by [date] desc)
from sample_table
where convert(time, [date]) < '06:30'
)
select total = sum(case when convert(time, c1.[date]) < '06:30'
then c1.value
else c1.value - c2.value
end)
from cte1 c1
left join cte2 c2 on c1.code = c2.code
and c1.rn = c2.rn
where c1.rn = 1

Answer 2

Try this
SELECT SUM([output]) AS [output]
FROM (
SELECT [latest]
,[before]
,(CASE WHEN [latest] = [before] THEN [latest]
ELSE [latest] - [before] END) AS [output]
FROM (
SELECT [code]
,MAX([value]) AS [latest]
,(SELECT MAX([value])
FROM [table]
WHERE [date] &lt CONVERT(datetime, CONVERT(varchar(10), CONVERT(date, [date])) + ' 06:30:00:000')
AND [code] = [t].[code]
GROUP BY [code]) AS [before]
FROM [table] AS [t]
GROUP BY [code]) AS [src]
) AS [rpt]

Answer 3

Try this puzzle:
CREATE TABLE TestTable
(
[date] datetime,
value int,
code varchar(10)
)
GO
INSERT INTO [dbo].[TestTable]
([date]
,[value]
,[code])
VALUES
('2018-09-13 06:20:52.803'
,100
,'M12'),
('2018-09-13 06:21:52.803'
,102
,'M12')
, ('2018-09-13 06:22:52.803'
,104
,'M12')
, ('2018-09-13 06:23:52.803'
,106
,'M12')
, ('2018-09-13 06:24:52.803'
,108
,'M12')
, ('2018-09-13 06:25:52.803'
,2
,'M77')
, ('2018-09-13 06:29:14.803'
,4
,'M77')
, ('2018-09-13 06:29:16.803'
,6
,'M77')
, ('2018-09-13 06:29:18.803'
,8
,'M77')
, ('2018-09-13 06:29:45.803'
,10
,'M77')
, ('2018-09-13 06:29:55.803'
,12
,'M77')
, ('2018-09-13 06:30:18.803'
,14
,'M77')
, ('2018-09-13 06:31:18.803'
,26
,'M77')
;WITH RESULT AS (
SELECT
TT.code
, MaxValueThatday = max(maxval.MAXVALUE )
, MaxValueBefore630NextDay = max(MAXValBefore630.MAXVALUE)
, ResultSubstraction =
CASE WHEN max(maxval.MAXVALUE ) <> max(MAXValBefore630.MAXVALUE)
THEN max(maxval.MAXVALUE ) - max(MAXValBefore630.MAXVALUE)
ELSE max(maxval.MAXVALUE )
END
FROM [dbo].[TestTable] TT
OUTER APPLY(
SELECT max(VALUE) MAXVALUE
, code
FROM [dbo].[TestTable] aa
WHERE Aa.code = tt.code
group by code
)maxval
OUTER APPLY(
SELECT max(A.VALUE) MAXVALUE
, code
FROM [dbo].[TestTable] A
WHERE DATEPART(HOUR,[DATE]) <= 6 AND DATEPART(MINUTE,[DATE]) < 30
and A.code = tt.code
group by code
)MAXValBefore630
where ( [DATE] > DATEADD(MINUTE,390,CAST({ fn CURDATE()} AS DATETIME) ) ) --6:30 today
group by tt.code
)
SELECT SUM(ResultSubstraction)
FROM RESULT