Split row based on start end date SQL Server

Question

Let's say I have these values in a table

Package | Start Date | End date 
---------------------------------
PKG123  | 01-02-2013 | 31-01-2016
PKG456  | 15-06-2010 | 14-06-2014

I want to write a select statement that should give me results like:

Package | Start Date | End date
-----------------------------------
PKG123  | 01-02-2013 | 31-01-2014
PKG123  | 01-02-2014 | 31-01-2015
PKG123  | 01-02-2015 | 31-01-2016
PKG456  | 15-06-2010 | 14-06-2011
PKG456  | 15-06-2011 | 14-06-2012
PKG456  | 15-06-2012 | 14-06-2013
PKG456  | 15-06-2013 | 14-06-2014

Is there a way to do it in TSQL?

Please note that I am not looking for a complete list of dates between two dates but looking for splitting of one row into multiple rows based on a duration of 12 months.

I am using SQL Server 2008 R2.

Answer 1

This is how you can do it using a recursive CTE:

;with CTE as (
  select package, startDate, EndDate from data
  union all
  select package, dateadd(month, 12, startDate), EndDate
  from CTE where EndDate > dateadd(month, 12, startDate)
)

select 
  package,
  startdate,
  case when enddate <= dateadd(month, 12, startdate)
    then enddate else dateadd(day, -1, dateadd(month, 12, startdate)) end
    as enddate
From
  CTE 
order by package, startdate

The CTE will take the rows from the table, and then recursively select new row if the startdate + 12 month is less than the end date. The select outside the CTE will determine which value from the row to be used, startdate + 12 months or end date.

SQL Fiddle: http://sqlfiddle.com/#!6/5bfbf/4