SQL Date Range Split

Question

Can you please let me know the SQL to split date ranges when they overlap?

Data (sample data with a date range and possibly other columns):

    Col1 From         


        

Answer 1

Skliwz's answer adapted for SQL Server:

DECLARE @DateTest TABLE 
(
    FromDate datetime,
    ToDate datetime 
)

insert into @DateTest (FromDate, ToDate)
(
select cast('1/1/2008' as datetime), cast('12/31/2010' as datetime)
union
select cast('1/1/2009' as datetime), cast('12/31/2012' as datetime)
union
select cast('1/1/2009' as datetime), cast('12/31/2014' as datetime)
)

SELECT 
  FromDate , min(ToDate)
FROM (
  SELECT t1.FromDate, t2.ToDate
  FROM 
    @DateTest t1, 
    @DateTest t2
  WHERE t1.FromDate < t2.ToDate

  UNION

  SELECT dateadd(DAY, 1, t1.ToDate), t2.ToDate
  FROM 
    @DateTest t1, 
    @DateTest t2
  WHERE dateadd(DAY, 1, t1.ToDate) < t2.ToDate
) allRanges
group by FromDate