Как переформатировать DateTime в Sql с методом потолка или пола?

Question

мне нужна эта таблица, посмотрите пожалуйста TABLE2

---

Table1

VisitingCount Дата
1 ------------------- 15: 09
3 ------------------- 15: 10
7 ------------------- 15: 15
1 ------------------- 15: 39
2 ------------------- 15: 40
3 ------------------- 15: 47

---

Как я могу изменить эту таблицу под таблицей

---

Table2

VisitingCount Дата
11 ------------------- 15: 00-15: 30
6 ------------------- 15: 30-16: 00

Итак, я написал некоторые пользовательские функции sql, смотрите ниже:

create FUNCTION [dbo].[fn_GetActivityLogsArranger]
(
@time AS nvarchar(max)
)

RETURNS  nvarchar(max)
AS
BEGIN
declare @Return varchar(30)

select @Return = case 
when @time between '00:00' and '00:30' then '00:00-00:30'
when @time between '00:30' and '01:00' then '00:30-01:00'
when @time between '01:00' and '01:30' then '01:00-01:30'

when @time between '01:30' and '02:00' then '01:30-02:00' 
when @time between '02:00' and '02:30' then '02:00-02:30' 
when @time between '02:30' and '03:00' then '02:30-03:00' 
when @time between '03:00' and '03:30' then '03:00-03:30' 
when @time between '03:30' and '04:00' then '03:30-04:00' 
when @time between '04:00' and '04:30' then '04:00-04:30' 
when @time between '04:30' and '05:00' then '04:30-05:00' 
when @time between '05:00' and '05:30' then '05:00-05:30'

when @time between '05:30' and '06:00' then '05:30-06:00' 
when @time between '06:00' and '06:30' then '06:00-06:30' 
when @time between '06:30' and '07:00' then '06:30-07:00' 
when @time between '07:00' and '07:30' then '07:00-07:30' 
when @time between '07:30' and '08:00' then '07:30-08:00' 
when @time between '08:00' and '08:30' then '08:00-08:30' 
when @time between '08:30' and '09:00' then '08:30-09:00' 
when @time between '09:00' and '09:30' then '09:00-09:30'

when @time between '09:30' and '10:00' then '09:30-10:00' 
when @time between '10:00' and '10:30' then '10:00-10:30' 
when @time between '10:30' and '11:00' then '10:30-11:00' 
when @time between '11:00' and '11:30' then '11:00-11:30' 
when @time between '11:30' and '12:00' then '11:30-12:00' 
when @time between '12:00' and '12:30' then '12:00-12:30' 
when @time between '12:30' and '13:00' then '12:30-13:00' 
when @time between '13:00' and '13:30' then '13:00-13:30'


when @time between '13:30' and '14:00' then '13:30-14:00' 
when @time between '14:00' and '14:30' then '14:00-14:30'
when @time between '14:30' and '15:00' then '14:30-15:00'
when @time between '15:00' and '15:30' then '15:00-15:30'
when @time between '15:30' and '16:00' then '15:30-16:00'
when @time between '16:00' and '16:30' then '16:00-16:30'
when @time between '16:00' and '16:30' then '16:00-16:30' 
when @time between '16:30' and '17:00' then '16:30-17:00' 
when @time between '17:00' and '17:30' then '17:00-17:30' 
when @time between '17:30' and '18:00' then '17:30-18:00'
when @time between '18:00' and '18:30' then '18:00-18:30' 


when @time between '18:30' and '19:00' then '18:30-19:00'
when @time between '19:00' and '19:30' then '19:00-19:30'
when @time between '19:30' and '20:00' then '19:30-20:00'
when @time between '20:00' and '20:30' then '20:00-20:30'
when @time between '20:30' and '21:00' then '20:30-21:00'
when @time between '21:00' and '21:30' then '21:00-21:30'
when @time between '21:30' and '22:00' then '21:30-22:00'
when @time between '22:00' and '22:30' then '22:00-22:30'
when @time between '22:30' and '23:00' then '22:30-23:00'
when @time between '23:00' and '23:30' then '23:00-23:30'
when @time between '23:30' and '24:00' then '23:30-:24:00'

else 'Unknown'
end
 Return @Return
end
 

---

Итак, я назвал этот UDF в моем sql-запросе. Итак, результат верный.

---

select Count(Page) as VisitingCount,[Time]
from
( SELECT Page,Date,[user],
        dbo.fn_GetActivityLogsArranger(CONVERT(VARCHAR(5),Date, 108)) as [Time]
        FROM scr_SecuristLog
) scr_SecuristLog
where
        Date between '2009-05-06' and '2009-05-07'
and
        [user] in
(       select USERNAME
        from scr_CustomerAuthorities
        where customerID=Convert(varchar,4)
        and ID=Convert(varchar,43)
)
group by [Time] order by [Time] asc 

dbo.fn_GetActivityLogsArranger (CONVERT (VARCHAR (5), Date, 108)) ... метод функции не является эффективным методом. Так как; написание слишком большого количества сравнений «когда-то» не является достаточным способом получения данных. Есть ли такой метод, как: "Math.Round ()" в SQL не C #.

Например:

Выполнить (11:28) Результат: 11:00, но Выполнить (11:31) Результат: 12:00

Answer 1

Я рекомендую вам посмотреть мой ответ в предыдущей теме, но, похоже, это работает:

declare @t datetime
set @t = '2009-05-06 12:29.997'
--truncate anything smaller than minute
set @t = cast (@t as smalldatetime)
select @t
select 
    case
        when datepart(minute, @t) >= 30
            then dateadd(minute, 60-(datepart(minute, @t)), @t)
        else dateadd(minute, -(datepart(minute, @t)), @t)
    end

Answer 2

Не лучше было бы преобразовать даты в количество минут, начиная с полуночи, и использовать модуль по модулю для преобразования дат в период времени (полчаса в вашем случае).

Например:

• DATEDIFF(mi, '2009-05-06', '2009-05-06 00:15') / 30 дает 0

• DATEDIFF(mi, '2009-05-06', '2009-05-06 00:45') / 30 дает 1

Таким образом, SQL-запрос будет выглядеть примерно так:

DECLARE 
    @midnight AS smalldatetime

SET @midnight = dbo.truncatetime(GETDATE()) -- you have to write dbo.truncatetime()

SELECT
    SUM(VisitingCount) AS VisitingCount,
    expression to convert time in minutes to time period
FROM
    TABLE1
GROUP BY
    DATEDIFF(mi, @midnight, Date) / 30 -- should give 0, 1 for every next half of hour