Group rows by contiguous date ranges for groups of values

Question

Consider some table T, ordered by Col1, Col2, Date1, Date2:

Col1    Col2    Date1         Date2          rate
ABC     123     11/4/2014         


        

Answer 1

You can identify the groups by using the difference of row_numbers(). Consecutive values will have a constant.

select col1, col2, date1, min(date2), max(date2), rate
from (select t.*,
             (row_number() over (partition by col1, col2, date1 order by date2) -
              row_number() over (partition by col1, col2, date1, rate order by date2)
             ) as grp
      from table t
     ) t
group by col1, col2, date1, rate, grp