Convert Date Range to Individual Days - sql

Question

A table called VolumeRequest stores the volume requests by accounts for a date range.
AccountId StartDate EndDate DailyVolume
670 2013-07-01 00:00:00.000 2013-07-31 00:00:00.000 10
670 2013-07-01 00:00:00.000 2013-07-31 00:00:00.000 1050
670 2013-07-10 00:00:00.000 2013-07-10 00:00:00.000 -350
670 2013-07-24 00:00:00.000 2013-07-26 00:00:00.000 -350
673 2013-06-01 00:00:00.000 2013-07-31 00:00:00.000 233
I need to display the requests on daily basis where volume is summed by day by account for a given date range like for month of July the report is like below. The date start and end dates of the volume requests need to be trimmed for the given report dates
AccountId Date Volume
670 2013-07-01 00:00:00.000 1060
670 2013-07-02 00:00:00.000 1060
.
.
670 2013-07-10 00:00:00.000 710
.
.
670 2013-07-24 00:00:00.000 710
670 2013-07-25 00:00:00.000 710
670 2013-07-26 00:00:00.000 710
.
.
670 2013-07-31 00:00:00.000 1060
673 2013-07-01 00:00:00.000 233
.
.
673 2013-07-31 00:00:00.000 233
Right now I am using table Variables and loops to achieve it which I know is not a good way to code.
DECLARE #sDate DATETIME, #eDate DATETIME , #volume DECIMAL (10, 4), rstartdate DATETIME, #renddate DATETIME , #loopcount INT
SET #sdate = '4/1/2013'
SET #edate = '4/30/2013'
DECLARE #VolumeRequest TABLE
(
ID INT IDENTITY (1, 1) PRIMARY KEY,
Aid INT,
Startdate DATETIME,
Enddate DATETIME,
volume DECIMAL (14, 4)
)
DECLARE #DailyRequest TABLE
(
ID INT IDENTITY (1, 1) PRIMARY KEY,
Accountid INT,
ReadDate DATETIME,
Volume DECIMAL (14, 4)
)
INSERT INTO #VolumeRequest
SELECT Accountid,
( CASE
WHEN #sdate > startdate THEN #sdate
ELSE startdate
END ),
( CASE
WHEN #edate < enddate THEN #edate
ELSE enddate
END ),
dailyvolume
FROM VolumeRequest
WHERE Startdate <= #edate
AND Enddate >= #sdate
AND isnull (deprecated, 0) != 1
--loop to breakdown the volume requests into daily requests
SET #loopcount = 1
WHILE #loopcount <= (SELECT MAX(ID)
FROM #VolumeRequest)
BEGIN
SELECT #volume = volume,
#rstartdate = Startdate,
#renddate = Enddate
FROM #VolumeRequest
WHERE ID = #loopcount
WHILE #rstartdate <= #renddate
BEGIN
INSERT INTO #DailyRequest
SELECT #currentaid,
#rstartdate,
#volume
SET #rstartdate = DATEADD(day, 1, #rstartdate)
END
SET #LoopCount = #LoopCount + 1
END
I am looking for ways which don't involve loops or cursors. I found a Similar Question. The answers there didn't help me.

Answer 1

I like to use a Dates table such as
CREATE TABLE #Dates(
DateId INT,
CalendarDate DATETIME)
filled with dates for whatever range you need. I use this table to join to tables such as VolumeRequest to retrieve the output you requested.
SELECT
v.AccountId,
d.CalendarDate,
SUM(v.DailyVolume)
FROM
#Dates d INNER JOIN
VolumeRequest v ON
d.CalendarDate >= v.StartDate AND
d.CalendarDate <= v.EndDate
group by
d.CalendarDate,
v.AccountId
to fill the #Dates table, I use something like this:
declare #startdate datetime = '6/1/13', #enddate datetime = '7/31/13'
create table #Dates(CalendarDate datetime)
insert into #Dates(CalendarDate)
select
dateadd(dd, rid-1, #startdate) as calendardate
from (
select
ROW_NUMBER() over(order by o.object_id) as rid
From
sys.objects o cross apply
sys.objects o2
) dates
where
dateadd(dd, rid-1, #startdate) >= #startdate and dateadd(dd, rid-1, #startdate) <= #enddate
Modify to meet your date range needs.

Answer 2

SQLFiddle demo
Using WITH clause and recursion we generate Days table with all days between MIN and MAX dates.
Then generate table Accounts with distinct AccountID.
Finally JOIN all these tables and group all with SUM.
WITH MINMAX as
( SELECT MIN(StartDate) as MinDate,
MAX(EndDate) as MaxDate
from T
),
DAYS as
( SELECT MinDate as D from MINMAX
UNION ALL
SELECT D+1 as D FROM DAYS WHERE D+1<=
(
SELECT MaxDate FROM MINMAX
)
),
Accounts as
(
select distinct AccountID from T
)
select A.AccountId,Days.D,sum(T.DailyVolume) from Days
CROSS JOIN Accounts A
JOIN T on A.AccountID=T.AccountID
AND
Days.D between T.StartDate and T.EndDate
GROUP BY A.AccountId,Days.D
ORDER BY A.AccountId,Days.D
OPTION (MAXRECURSION 10000)