Convert Date Range to Individual Days

Question

A table called VolumeRequest stores the volume requests by accounts for a date range.

AccountId   StartDate                       EndDate                    


        

Answer 1

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)