SQL TSQL for Workers per Hour - sql

Question

I have a log with fingerprint timestamps as follows:
Usr TimeStamp
-------------------------
1 2015-07-01 08:01:00
2 2015-07-01 08:05:00
3 2015-07-01 08:07:00
1 2015-07-01 10:05:00
3 2015-07-01 11:00:00
1 2015-07-01 12:01:00
2 2015-07-01 13:03:00
2 2015-07-01 14:02:00
1 2015-07-01 16:03:00
2 2015-07-01 18:04:00
And I wish an output of workers per hour (rounding to nearest hour)
The theoretical output should be:
7:00 0
8:00 3
9:00 3
10:00 2
11:00 1
12:00 2
13:00 1
14:00 2
15:00 2
16:00 1
17:00 1
18:00 0
19:00 0
Can anyone think on how to approach this as SQL or if no other way, through TSQL?
Edit: The timestamps are logins and logouts of the different users. So at 8am 3 users logged in and the same 3 are still working at 9am. One of them leaves at 10am. etc

Answer 1

To start with you can use datepart to get hours for the days as following and then use group by user
SELECT DATEPART(HOUR, GETDATE());
SQL Fiddle
SELECT Convert(varchar(5),DATEPART(HOUR, timestamp)) + ':00' as time,
count(usr) as users
from tbl
group by DATEPART(HOUR, timestamp)

Answer 2

You need a datetime hour table to do this.
Note : This is just a example of showing how the query should work for one day. Replace the CTE with datetime hour table. In datetime hour table every date should start with 07:00:00 hour and end with 19:00:00 hour
When you want to do this for more than one day then you may have to include the Cast(dt.date_time AS DATE) in select and group by to differentiate the hour belong to which day
WITH datetime_table
AS (SELECT '2015-07-01 07:00:00' AS date_time
UNION ALL
SELECT '2015-07-01 08:00:00'
UNION ALL
SELECT '2015-07-01 09:00:00'
UNION ALL
SELECT '2015-07-01 10:00:00'
UNION ALL
SELECT '2015-07-01 11:00:00'
UNION ALL
SELECT '2015-07-01 12:00:00'
UNION ALL
SELECT '2015-07-01 13:00:00'
UNION ALL
SELECT '2015-07-01 14:00:00'
UNION ALL
SELECT '2015-07-01 15:00:00'
UNION ALL
SELECT '2015-07-01 16:00:00'
UNION ALL
SELECT '2015-07-01 17:00:00'
UNION ALL
SELECT '2015-07-01 18:00:00'
UNION ALL
SELECT '2015-07-01 19:00:00')
SELECT Datepart(hour, dt.date_time),
Hour_count=Count(t.id)
FROM datetime_table dt
LEFT OUTER JOIN Yourtable t
ON Cast(t.dates AS DATE) = Cast(dt.date_time AS DATE)
AND Datepart(hour, t.dates) =
Datepart(hour, dt.date_time)
GROUP BY Datepart(hour, dt.date_time)
SQLFIDDLE DEMO

Answer 3

You just need to group by hours and date. Check this below query and hope this helps you:
Create table #t1
(
usr int,
timelog datetime
)
Insert into #t1 values(1, '2015-07-01 08:01:00')
Insert into #t1 values(2, '2015-07-01 08:05:00')
Insert into #t1 values(3, '2015-07-01 08:07:00')
Insert into #t1 values(1, '2015-07-01 10:05:00')
Insert into #t1 values(3, '2015-07-01 11:00:00')
Insert into #t1 values(1, '2015-07-01 12:01:00')
Insert into #t1 values(2, '2015-07-01 13:03:00')
Insert into #t1 values(2, '2015-07-01 14:02:00')
Insert into #t1 values(1, '2015-07-01 16:03:00')
Insert into #t1 values(2, '2015-07-01 18:04:00')
Select cast(timelog as varchar(11)) as LogDate, Datepart(hour, timelog) as LogTime, count(usr) as UserCount from #t1
Group by Datepart(hour, timelog), cast(timelog as varchar(11))

Answer 4

The harder part is creating the zeros where data is missing. The usual approach is to generate a list of all possible "slots" and then do an outer join to the actual data. I'm assuming that you only want to run this for a single day at a time.
My approach, which is just an example, works because it does a cross join of two tables with 6 and 4 rows respectively and 6 times 4 is 24.
select f1.d * 6 + f0.d, coalesce(data.cnt, 0)
from
(
select 0 as d union all select 1 union all select 2 union all
select 3 union all select 4 union all select 5
) as f0,
(
select 0 as d union all select 1 union all
select 2 union all select 3
) as f1
left outer join
(
select
cast(datepart(hh, TimeStamp) as varchar(2)) + ':00' as hr,
count(*) as cnt
from LOG
group by datepart(hh, TimeStamp)
) as data
on data.hr = f1.d * 6 + f0.d

Answer 5

First you need to round up time to the closest hour
DATEADD(HOUR, DATEDIFF(HOUR, 0, DATEADD(MI, 30, TimeStamp)), 0)
As you see first we add 30 minutes to the original time (DATEADD(MI, 30, TimeStamp))
This approach will round up 08:04 to 08:00 or 07:58 to 8:00 too.
As I assume some workers can start working little bid early
SELECT DATEADD(HOUR, DATEDIFF(HOUR, 0, DATEADD(MI, 30, TimeStamp)), 0) As FingertipTime
FROM Fingertips
You can create a Computed column if you use rounded timestamp often
ALTER TABLE Fingertips ADD RoundedTimeStamp AS (DATEADD(HOUR, DATEDIFF(HOUR, 0, DATEADD(MI, 30, TimeStamp)), 0));
For comparing timestamps with constants of work hours you can find different methods. I will use a variable of type TABLE where i generate work hours for current day
Then using LEFT JOIN and GROUP BY we get quantity of timestamps
DECLARE #WorkHours TABLE(WorkHour DATETIME)
INSERT INTO #WorkHours (WorkHour) VALUES
('2015-07-01 07:00'),
('2015-07-01 08:00'),
('2015-07-01 09:00'),
('2015-07-01 10:00'),
('2015-07-01 11:00'),
('2015-07-01 12:00'),
('2015-07-01 13:00'),
('2015-07-01 14:00'),
('2015-07-01 15:00'),
('2015-07-01 16:00'),
('2015-07-01 17:00'),
('2015-07-01 18:00'),
('2015-07-01 19:00')
SELECT wh.Workhour
, COUNT(ft.TimeStamp) As Quantity
FROM #WorkHours wh
LEFT JOIN Fingertips ft ON ft.RoundedTimeStamp = wh.WorkHour
GROUP BY wh.WorkHour
Check this SQL Fiddle

Answer 6

Many separate parts that have to be glued together to get this done.
First rounding, this is easily done with obtaining the hour part of the date + 30 minutes. Then determine start and end records. If there are no fields to indicate this and assuming the first occurrence of a day is the login or start, you can use row_number and use the odd numbers as start records.
Then start and end have to be coupled, in sql server 2012 and higher this can be easily done with the lead function
To get the missing hours a sequence has to be created with all the hours. Several options for this (good link here), but I like the approach of using row_number on a table that is sure to contain enough rows (with a proper column for order by), such as sys.all_objects used in the link. That way hours 7 to 19 could be created as: select top 13 ROW_NUMBER() over (order by object_id) + 6 [Hour] from sys.all_objects
If there's only one date to check on, the query can simple left join on the hour of the timestamp fingerprints. If there are more dates, a second sequence could be created cross applied to the times to get all dates. Assuming the one date, final code would be:
declare #t table(Usr int, [timestamp] datetime)
insert #t values
(1 , '2015-07-01 08:01:00'),
(2 , '2015-07-01 08:05:00'),
(3 , '2015-07-01 08:07:00'),
(1 , '2015-07-01 10:05:00'),
(3 , '2015-07-01 11:00:00'),
(1 , '2015-07-01 12:01:00'),
(2 , '2015-07-01 13:03:00'),
(2 , '2015-07-01 14:02:00'),
(1 , '2015-07-01 16:03:00'),
(2 , '2015-07-01 18:04:00'),
(2 , '2015-07-01 18:04:00')
;with usrHours as
(
select Usr, datepart(hour, DATEADD(minute,30, times.timestamp)) [Hour] --convert all times to the rounded hour (rounding by adding 30 minutes)
, ROW_NUMBER() over (partition by usr order by [timestamp] ) rnr
from #t times --#t should be your logging table
), startend as --get next (end) hour by using lead
(
select Usr, [hour] StartHour , LEAD([Hour]) over (partition by usr order by rnr) NextHour ,rnr
from usrHours
),hours as --sequence of hours 7 to 19
(
select top 13 ROW_NUMBER() over (order by object_id) + 6 [Hour] from sys.all_objects
)
select cast([Hour] as varchar) + ':00' [Hour], COUNT(startend.usr) Users
from hours --sequence is leading
left join startend on hours.Hour between startend.StartHour and startend.NextHour
and rnr % 2 = 1 --every odd row number is a start time
group by Hours.hour

Answer 7

Here is my final working code:
create table tsts(id int, dates datetime)
insert tsts values
(1 , '2015-07-01 08:01:00'),
(2 , '2015-07-01 08:05:00'),
(3 , '2015-07-01 08:07:00'),
(1 , '2015-07-01 10:05:00'),
(3 , '2015-07-01 11:00:00'),
(1 , '2015-07-01 12:01:00'),
(2 , '2015-07-01 13:03:00'),
(2 , '2015-07-01 14:02:00'),
(1 , '2015-07-01 16:03:00'),
(2 , '2015-07-01 18:04:00')
select horas.hora, isnull(sum(math) over(order by horas.hora rows unbounded preceding),0) as Employees from
(
select 0 as hora union all
select 1 as hora union all
select 2 as hora union all
select 3 as hora union all
select 4 as hora union all
select 5 as hora union all
select 6 as hora union all
select 7 as hora union all
select 8 as hora union all
select 9 as hora union all
select 10 as hora union all
select 11 as hora union all
select 12 as hora union all
select 13 as hora union all
select 14 as hora union all
select 15 as hora union all
select 16 as hora union all
select 17 as hora union all
select 18 as hora union all
select 19 as hora union all
select 20 as hora union all
select 21 as hora union all
select 22 as hora union all
select 23
) as horas
left outer join
(
select hora, sum(math) as math from
(
select id, hora, iif(rowid%2 = 1,1,-1) math from
(
select row_number() over (partition by id order by id, dates) as rowid, id, datepart(hh,dateadd(mi, 30, dates)) as hora from tsts
) as Q1
) as Q2
group by hora
) as Q3
on horas.hora = Q3.hora
SQL Fiddle