SQL very ugly GROUP BY
Question
Daylight savings calculation. We do have a very ugly working model below.
Have seen this - SQL - Ugly combination of GROUP BY and COALESCE
If we can set variables.. This does not work - also, have removed the count(*) to illustrate the issue we are seeing..
Declare @subtractor int;
select top 10 case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then
Set @subtractor = 5;
else
Set @subtractor = 6;
end
CAST(DATEADD(HH, -@subtractor,LOGGED_TIME) AS date) AS ForDate
, txtW=DATENAME(WEEKDAY, DATEADD(HH, -@subtractor,LOGGED_TIME))
, intW=DATEPART(WEEKDAY, DATEADD(HH, -@subtractor,LOGGED_TIME))
, intH=DATEPART(HOUR, DATEADD(HH, -@subtractor,LOGGED_TIME))
from SUPPORT_DATABASE.dbo.LOG (nolock)
This does work.. However, it is a very, very ugly GROUP BY.. Is there a way to clean this up?
select top 10
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then CAST(dateadd(hh,-5,LOGGED_TIME) AS date) -- DST
else CAST(dateadd(hh,-6,LOGGED_TIME) AS date) -- DST
end as ForDate,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATENAME(WEEKDAY,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATENAME(WEEKDAY,dateadd(hh,-6,LOGGED_TIME)) -- DST
end as txtW,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATENAME(WEEKDAY,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATENAME(WEEKDAY,dateadd(hh,-6,LOGGED_TIME)) -- DST
end as intW,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATEPART(HOUR,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATEPART(HOUR,dateadd(hh,-6,LOGGED_TIME)) -- DST
end as intH
, COUNT(*) AS Totals
FROM SUPPORT_DATABASE.dbo.LOG WITH (nolock)
GROUP BY case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then CAST(dateadd(hh,-5,LOGGED_TIME) AS date) -- DST
else CAST(dateadd(hh,-6,LOGGED_TIME) AS date) -- DST
end,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATENAME(WEEKDAY,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATENAME(WEEKDAY,dateadd(hh,-6,LOGGED_TIME)) -- DST
end
,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATEPART(WEEKDAY,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATEPART(WEEKDAY,dateadd(hh,-6,LOGGED_TIME)) -- DST
end,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATEPART(HOUR,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATEPART(HOUR,dateadd(hh,-6,LOGGED_TIME)) -- DST
end
2 answers
solution1
2 ACCPTED 2014-02-25 17:51:26
You could wrap it in a cte, so you can just GROUP BY the aliases:
;WITH cte AS ( select
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then CAST(dateadd(hh,-5,LOGGED_TIME) AS date) -- DST
else CAST(dateadd(hh,-6,LOGGED_TIME) AS date) -- DST
end as ForDate,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATENAME(WEEKDAY,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATENAME(WEEKDAY,dateadd(hh,-6,LOGGED_TIME)) -- DST
end as txtW,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATENAME(WEEKDAY,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATENAME(WEEKDAY,dateadd(hh,-6,LOGGED_TIME)) -- DST
end as intW,
case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then DATEPART(HOUR,dateadd(hh,-5,LOGGED_TIME)) -- DST
else DATEPART(HOUR,dateadd(hh,-6,LOGGED_TIME)) -- DST
end as intH
FROM SUPPORT_DATABASE.dbo.LOG WITH (nolock))
SELECT *,COUNT(*) CT
FROM cte
GROUP BY ForDate, txtW, intW, intH
That's a simple way to clean things up a little bit, sure it needs refactoring as well.
solution2
1 2014-02-25 17:58:25
You could just create a UDF:
CREATE FUNCTION dbo.YourFunctionName (@DateTime DATETIME)
RETURNS DATE
AS
BEGIN
RETURN
(
SELECT case
when @DateTime between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(@DateTime) as varchar(4)) as datetime)))
end
then CAST(dateadd(hh,-5,@DateTime) AS date) -- DST
else CAST(dateadd(hh,-6,@DateTime) AS date) -- DST
end
);
END
Then your query is simply:
SELECT dbo.YourFunctionName(LOGGED_TIME) AS ForDate,
DATENAME(WEEKDAY, dbo.YourFunctionName(LOGGED_TIME)) AS txtW
....
GROUP BY dbo.YourFunctionName(LOGGED_TIME);
Or, if you will never re-use this function and don't wnat to create it just for this, you can move your logic to an APPLY, then reference your new column:
SELECT fd.ForDate,
DATENAME(WEEKDAY, fd.ForDate) AS txtW
FROM ...
CROSS APPLY
(
SELECT case
when LOGGED_TIME between
case DATEPART(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-4,CAST('03/08/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))--2am minus 6 hours for conversion from UST going to DST
else dateadd(hh,-4,DATEADD(d,15-datepart(dw,CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('03/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
and
case DATEPART(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime))
when 1 then dateadd(hh,-3,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)) --2am minus 5 hours for conversion from UST going from DST
else dateadd(hh,-3,DATEADD(d,8-datepart(dw,CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)),CAST('11/01/'+CAST (YEAR(LOGGED_TIME) as varchar(4)) as datetime)))
end
then CAST(dateadd(hh,-5,LOGGED_TIME) AS date) -- DST
else CAST(dateadd(hh,-6,LOGGED_TIME) AS date) -- DST
end as ForDate
) AS fd
GROUP BY fd.ForDate;
Or finally you could use a subquery and only group in the outer query.
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