TS SQL - group by minute

Question

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.

Answer 1

SELECT COUNT (TS) from TABLE where TABLE.TS BETWEEN(starttime, endtime)

Answer 2

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.

Answer 3

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

Answer 4

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.