我必须按周编写数据库中站立支架数量的趋势报告。 我可以在下面的示例中获得按星期竖立的支架计数,并使用相同的查询进行拆解,但这不是我需要的。
SELECT COUNT(scaffID) Erected, WeekStart
FROM
(
SELECT ScaffID,
dateadd(week, datediff(day,0,Erected) / 7, 0) AS WeekStart
FROM Scaffolds
) o
GROUP BY WeekStart
我可以通过约会来获得我的站立支架,但我希望每个星期五的站立脚手架都说。
Declare @staticDate As DateTime
Set @staticDate = '2/1/2015'
Select COUNT(scaffID) As StandingScaffolds
from RequestInfo
Where ( ErectDate<= @staticDate )
And ( DismantleDate>= @staticDate
or DismantleDate Is NULL
)
这让我发疯,所以任何帮助都会非常感激。
菲尔
答案 0 :(得分:0)
这应该给你一些开始......
DECLARE
@startDate date = '2015-01-01',
@endDate date = '2015-01-28';
with myWeeks (myWeek) AS (
select DATEPART(WEEK,@startDate) myWeek
UNION ALL
select myWeek + 1 from myWeeks
where
myWeek < DATEPART(WEEK,@endDate)
)
select
w,
COUNT(s.Erected) standingScaffolds
from myWeeks w
left join Scaffolds s on
w.myWeek between DATEPART(WEEK,s.Erected) and DATEPART(WEEK,s.Dismantled)
答案 1 :(得分:0)
您可能希望为此生成日期表(=每天有一行的表)。然后,您可以将其与此表连接,以便轻松地进行计算。
select d.date, count(s.scaffID)
from date d, scaffolds s
where s.erected <= d.date and
(dismantled>= d.date or dismantled is NULL) and
d.date >= @stardate and
d.date <= enddate
group by d.date
希望这没关系,现在无法测试。
日期表在其他情况下也很有用,例如你可以在那里度假。