Need Oracle SQL to split up date/time range by day

Question

I am hoping to get some help to write some SQL that I have had no success writing myself.

I have a table with the data:

ID    StartDate             EndDat         


        

Answer 1

It is possible to do this in SQL. There are two tricks. The first is generating a series of numbers, which you can do with a CTE using connect.

The second is putting together the right logic to expand the dates, while keeping the right times for the beginning and end.

The following is an example:

with n as (
      select level n
      from dual connect by level <= 20
     ),
     t as (
      select 1 as id, to_date('01/01/2000 4', 'mm/dd/yyyy hh') as StartDate, to_date('01/03/2000 6', 'mm/dd/yyyy hh') as EndDate from dual union all
      select 2 as id, to_date('01/04/2000 8', 'mm/dd/yyyy hh') as StartDate, to_date('01/04/2000 12', 'mm/dd/yyyy hh') as EndDate from dual union all
      select 3 as id, to_date('01/05/2000', 'mm/dd/yyyy') as StartDate, to_date('01/06/2000', 'mm/dd/yyyy') as EndDate from dual
     )
select t.id,
       (case when n = 1 then StartDate
             else trunc(StartDate + n - 1)
        end) as StartDate,
       (case when trunc(StartDate + n - 1) = trunc(enddate)
             then enddate
             else trunc(StartDate + n)
        end)
from t join
     n
     on StartDate + n - 1 <= EndDate
order by id, StartDate

Here it is on SQLFiddle.

Answer 2

Thanks Gordon! It helped me a lot too. My unique comment is that I had to change the join clause from:

on StartDate + n - 1 <= EndDate

To:

on trunc(StartDate + n - 1) <= trunc(EndDate)

After this change it worked for me perfectly.