Here is the problem I am facing:
I got a large table containing rows, I want to group them by near time, more specifically the time difference less than 2 minutes, example as following
With following input data:
A 16:01:01
B 16:01:20
C 16:14:02
D 16:15:01
E 16:20:02
the expected result is
16:01:01 2
16:14:02 2
16:20:02 1
If you're using SQL server 2012, you'r in luck and you can use lag function and rolling total sum:
with cte as (
select
case
when datediff(mi, lag(data) over (order by data), data) <= 1 then 0
else 1
end as ch,
data
from test
), cte2 as (
select
data, sum(ch) over (order by data) as grp
from cte
)
select
min(data) as data, count(*) as cn
from cte2
group by grp
sql fiddle demo
SELECT CONVERT(VARCHAR(8),
DATEADD(minute, (DATEDIFF(n, 0, time) / 2) * 2, 0),
108),
COUNT(*)
FROM times
GROUP BY DATEDIFF(n, 0, time) / 2
Explanation:
CONVERT displays a DateTime in hh:mm:ss format (= 108).
DATEDIFF converts to minutes and then divides by two, rounding to an integer so each GROUP of 2 minutes resolves to the same integer.
DATEADD is used to convert this number of minutes back to a DateTime, having multiplied by 2 to get back to the correct (rounded) time.
See SQL Fiddle Demo
Declare #m_TestTable table
(
DateRecorded datetime
)
Insert into #m_TestTable Values ('16:01:01' )
Insert into #m_TestTable Values ('16:01:20' )
Insert into #m_TestTable Values ('16:14:02' )
Insert into #m_TestTable Values ('16:15:01' )
Insert into #m_TestTable Values ('16:20:01' );
With tblDifference as
(
Select Row_Number() OVER (Order by DateRecorded) as RowNumber,DateRecorded from #m_TestTable
)
select cur.DateRecorded as prvD, prv.DateRecorded as prvC, dateDiff(n, cur.DateRecorded,prv.DateRecorded) from tblDifference cur LEFT OUTER JOIN tblDifference prv
ON cur.RowNumber = prv.RowNumber + 1
this will give you the time difference in minutes between 2 rows. You can select any row that has a time difference less then 2 mins. It will also give you the upper and lower value.
It should be usefull to find any values closer then 2 minutes apart.
prvD prvC Diff
1900-01-01 16:01:01.000 NULL NULL
1900-01-01 16:01:20.000 1900-01-01 16:01:01.000 0
1900-01-01 16:14:02.000 1900-01-01 16:01:20.000 -13
1900-01-01 16:15:01.000 1900-01-01 16:14:02.000 -1
1900-01-01 16:20:01.000 1900-01-01 16:15:01.000 -5
Related
Is it possible to use the DATEADD function but exclude dates from a table?
We already have a table with all dates we need to exclude. Basically, I need to add number of days to a date but exclude dates within a table.
Example: Add 5 days to 01/08/2021. Dates 03/08/2021 and 04/08/2021 exist in the exclusion table. So, resultant date should be: 08/08/2021.
Thank you
A bit of a "wonky" solution, but it works. Firstly we use a tally to create a Calendar table of dates, that exclude your dates in the table, then we get the nth row, where n is the number of days to add:
DECLARE #DaysToAdd int = 5,
#StartDate date = '20210801';
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL))N(N)),
Tally AS(
SELECT 0 AS I
UNION ALL
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS I
FROM N N1, N N2, N N3), --Up to 1,000
Calendar AS(
SELECT DATEADD(DAY,T.I, #StartDate) AS D,
ROW_NUMBER() OVER (ORDER BY T.I) AS I
FROM Tally T
WHERE NOT EXISTS (SELECT 1
FROM dbo.DatesTable DT
WHERE DT.YourDate = DATEADD(DAY,T.I, #StartDate)))
SELECT D
FROM Calendar
WHERE I = #DaysToAdd+1;
A best solution is probably a calendar table.
But if you're willing to traverse through every date, then a recursive CTE can work. It would require tracking the total iterations and another column to substract if any traversed date was in the table. The exit condition uses the total difference.
An example dataset would be:
CREATE TABLE mytable(mydate date); INSERT INTO mytable VALUES ('20210803'), ('20210804');
And an example function run in it's own batch:
ALTER FUNCTION dbo.fn_getDays (#mydate date, #daysadd int)
RETURNS date
AS
BEGIN
DECLARE #newdate date;
WITH CTE(num, diff, mydate) AS (
SELECT 0 AS [num]
,0 AS [diff]
,DATEADD(DAY, 0, #mydate) [mydate]
UNION ALL
SELECT num + 1 AS [num]
,CTE.diff +
CASE WHEN DATEADD(DAY, num+1, #mydate) IN (SELECT mydate FROM mytable)
THEN 0 ELSE 1 END
AS [diff]
,DATEADD(DAY, num+1, #mydate) [mydate]
FROM CTE
WHERE (CTE.diff +
CASE WHEN DATEADD(DAY, num+1, #mydate) IN (SELECT mydate FROM mytable)
THEN 0 ELSE 1 END) <= #daysadd
)
SELECT #newdate = (SELECT MAX(mydate) AS [mydate] FROM CTE);
RETURN #newdate;
END
Running the function:
SELECT dbo.fn_getDays('20210801', 5)
Produces output, which is the MAX(mydate) from the function:
----------
2021-08-08
For reference the MAX(mydate) is taken from this dataset:
n diff mydate
----------- ----------- ----------
0 0 2021-08-01
1 1 2021-08-02
2 1 2021-08-03
3 1 2021-08-04
4 2 2021-08-05
5 3 2021-08-06
6 4 2021-08-07
7 5 2021-08-08
You can use the IN clause.
To perform the test, I used a W3Schools Test DB
SELECT DATE_ADD(BirthDate, INTERVAL 10 DAY) FROM Employees WHERE FirstName NOT IN (Select FirstName FROM Employees WHERE FirstName LIKE 'N%')
This query shows all the birth dates + 10 days except for the only employee with name starting with N (Nancy)
I need a query that returns all the hours of the day in 12 hour format
ex: 12:00 am, 1:00am, 2:00am etc. This is going to be used in SSRS as a selection field for a parameter for time. I need to select records within a date range and then from a time range in that date range. I have this query which returns the time in 24 hour format but it is not working properly in SSRS:
With CTE(N)
AS
(
SELECT 0
UNION ALL
SELECT N+30
FROM CTE
WHERE N+5<24*60
)
SELECT CONVERT(TIME,DATEADD(minute,N,0) ,108)
FROM CTE
OPTION (MAXRECURSION 0)
This is how I would do it:
DECLARE #t time(1) = '00:00'; --I use 1 as when I use REPLACE later it means that I can "identify" the correct :00 to remove
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL)) N(N)),
Tally AS(
SELECT TOP 24 ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 AS I
FROM N N1, N N2),
Times AS(
SELECT DATEADD(HOUR, I,#t) AS [Time]
FROM Tally)
SELECT T.[Time],
REPLACE(CONVERT(varchar(12),T.Time,9),':00.0',' ') AS TimeString
FROM Times T
ORDER BY T.[Time] ASC;
Note that I return both a time and varchar datatype; both are important as the ordering of the data for a varchar would be quite different to start with and if you are using SSRS, I suspect you want the value of TimeString as a presentation thing and not the actual value.
I am working on a stored procedure where I am dividing the number of rows by interval of month and day repeated in the specified date range.
Interval Month and Day = 7th April and 8th October
Example
For Date range 2014/01/01 and 2014/12/31, 7th April and 8th October are repeated 2 times so I will divide my statement by 2.
For Date range 2014/01/01 and 2015/09/01, 7th April came 2 and 8th October 1 so I will divide my statement by 3.
As others have stated, the question is a bit unclear, but I believe I know what you're trying to do. You are trying to find the number of times that a set of dates (only taking Month/Day into account) happen over a range of dates (set by #StartDate and #EndDate). I think the select count(*) from TableName part of the question is a distraction, as you already know how to do that. Below is an answer on how to get the denominator, which is what you are trying to figure out how to do.
declare #StartDate date = '2014-01-01'
, #EndDate date = '2014-12-31'
, #DenVal int --Denominator Value
create table #dates_of_interest
(
month_nbr tinyint not null
, day_nbr tinyint not null
)
insert into #dates_of_interest
values (4, 7) --7th of April
, (10, 8) --8th of October
; with date_list as
(
--use a Recursive CTE to generate a list of all the dates in the given range.
select #StartDate as dt
union all
select dateadd(d,1,dt) as dt
from date_list
where 1=1
and dt < #EndDate
)
--Get the output of the Recursive CTE along with Month/Day numbes
select dt
, datepart(m,dt) as month_nbr
, datepart(d,dt) as day_nbr
into #list_of_dates
from date_list as dl
option (maxrecursion 32767) --set to max possible levels of recursion (might want to lower this number)
--Set the Denominator to the results of the sum(case/when) AKA countif
set #DenVal =
(
select sum(case when di.month_nbr is null and di.day_nbr is null then 0 else 1 end)
from #list_of_dates as ld
left join #dates_of_interest as di on ld.month_nbr = di.month_nbr
and ld.day_nbr = di.day_nbr
)
Print #DenVal
Both examples of 1/1/2014 - 12/31/2014 and 1/1/2014 - 9/1/2015 come up with the desired results of 2 and 3 respectively. There may be other ways of accomplishing this, but I thought that a Recursive CTE was the best option.
I would like to calculate an average of a value in one year. I have a historical data table that saves the changes of the value in time.
I know how to do this with a (sub)query for each individual month, but Im hopeful that there is a simple way to do it in one query.
Example:
ID, Value, DateUntilActivity
1, 10.00, 2014-03-01
2, 5.00, 2014-05-01
3, 3.00, 2014-07-01
4, 12.00, 2014-10-01
So - the correct calculation here is:
(2x10.00 + 2x5.00 + 2x3.00 + 3x12.00 + 3x<current_value_in_a_different_table>)/12
The calculation includes the number of moths the data was active for - the first value, 10.00 was valid in 2 months - January and February.
And consider the value current_value_in_a_different_table a fixed value.
Also, it needs to work on MSSQL server 2005.
Thank you in advance!
;with cte as
(
select value, DateUntilActivity from yourtable
union
select 100 as currentvalue, '2015-1-1' from yourothertable
)
select avg(value)
from
(
select (select top 1 value from cte where DateUntilActivity>DATEADD(MONTH,number, '2014-1-1') order by DateUntilActivity ) as value
from master..spt_values
where type='p' and number <=11
) v
If my memory is wrong and you can't use a CTE, this is equivalent to
select avg(value)
from
(
select
(select top 1 value
from
(
select value, DateUntilActivity from yourtable
union
select 100 as currentvalue, '2015-1-1' from yourothertable
) v
where DateUntilActivity>DATEADD(MONTH,number, '2014-1-1') order by DateUntilActivity ) as value
from master..spt_values
where type='p' and number <=11
) v
I have a table with timestamps. What is the proper query to get the records counts for each minute for the last hour.
I.e. if now is 2:25, I want to know how many record were between 1:25 and 1:26, 1:26 and 1:27, and so on, so I have 60 results.
This will return a count of results for each minute (where you have records) in the last hour
SELECT DATEPART(n, time_stamp) AS minute, COUNT(*) as results
FROM table_name
WHERE time_stamp > DATEADD(hh, -1, GETDATE())
GROUP BY DATEPART(n, time_stamp)
This may return less than 60 results, depending on the data. If you have to have 60 results, the query is slightly different. This uses a Common Table Expression to generate a list of 60 numbers and a correlated sub-query to get the results for each minute:
WITH numbers ( num ) AS (
SELECT 1 UNION ALL
SELECT 1 + num FROM numbers WHERE num < 60 )
SELECT num AS minute,
(SELECT COUNT(*) AS results
FROM table_name
WHERE DATEPART(n, time_stamp) = num
AND time_stamp > DATEADD(hh, -1, GETDATE())
FROM numbers
To see the results, replace DATEADD(hh, -1, GETDATE()) with DATEADD(mi, -15, GETDATE()) and you'll get the results for the last 15 minutes and 0 for other minutes.
This is an alternative I have found useful for determining how many records are inserted or updated per minute. The nice thing about having your date format as a variable up front is that you can easily change it to analyze per hour instead. Hope this helps!
DECLARE #dateFormat as varchar(max) = 'yyyy-MM-dd HH:mm'
SELECT format(timeColumn, #dateFormat) AS minute, COUNT(*) as results
FROM yourTable
WHERE timeColumn > DATEADD(hh, -1, GETDATE())
GROUP BY format(timeColumn, #dateFormat)
ORDER BY 1
As you edited the question, I edit my answer. If I have understood you correctly, you want to look only at the past hour - that is, a timespan from one hour before the request is made to the current time. This is how I'd do it:
SELECT
COUNT(yourTimeStamp)
FROM yourTable
WHERE DATEADD('hh', -1, GetDate()) <= yourTimeStamp
AND yourTimeStamp < GetDate()
GROUP BY DATEPART('mm', yourTimeStamp)
I am not entirely sure that the syntax is exact. When coding in MSSQL, I would use the CURRENT_TIMESTAMP for the current time, MINUTE instead of DATEPART etc, but you get the idea for the solution.
DATEPART is what you're looking for:
declare #times table
(
someTime datetime
)
INSERT INTO #Times (sometime) values ('jan 12 2008 12:23')
INSERT INTO #Times (sometime) values ('jan 12 2008 12:34')
INSERT INTO #Times (sometime) values ('jan 12 2008 12:35')
INSERT INTO #Times (sometime) values ('jan 12 2008 12:25')
INSERT INTO #Times (sometime) values ('jan 12 2008 12:02')
INSERT INTO #Times (sometime) values ('jan 12 2008 12:09')
INSERT INTO #Times (sometime) values ('jan 12 2008 12:35')
select DATEPART(mi,sometime) AS Minute, count(*) AS NumOccurances
from #Times
WHERE SomeTime BETWEEN #Lower AND #Upper
GROUP BY DATEPART(mi, sometime)
order by NumOccurances DESC
Result:
Minute NumOccurances
35 2
2 1
9 1
23 1
25 1
34 1
If you want to group results by minute, then you can use a formatted string. This will group by number of minutes since 1/1/1900 not minute within day.
WITH formatted AS (
SELECT FORMAT(<your_datetime_column>, 'yyyy-MM-dd HH:mm') AS minute_text
FROM <your_table>
)
SELECT minute_text, COUNT(*) AS number_of_rows
FROM formatted
GROUP BY minute_text
ORDER BY 1 DESC
Here's my fixed up version of Robin's answer. I made it output the errors in the correct order and output the time as well instead of just the number which isn't super useful if you're charting this out.
WITH numbers ( num ) AS (
SELECT 1 UNION ALL
SELECT 1 + num FROM numbers WHERE num < 60 )
SELECT (SELECT DATEADD(n, -num, GETDATE())) AS TimeStamp,
(SELECT COUNT(*) AS results
FROM ErrorLogs
WHERE DATEPART(n, TimeStamp) = DATEPART(n, DATEADD(n, -num, GETDATE()))
AND TimeStamp > DATEADD(hh, -1, GETDATE())) as Count
FROM numbers
SELECT COUNT (TS) from TABLE where TABLE.TS BETWEEN(starttime, endtime)