print start and end date in one row for continous or overlaping date ranges in oracle SQL

Question

I would like to print in one row start date and end date for continous or overlaping date ranges.

here is the data

create table orders (
po varchar2(6),
st         


        

Answer 1

There is an elegant (and efficient) solution using the match_recognize clause (which requires Oracle 12.1 or higher).

select po, startdate, enddate
from   orders
match_recognize (
  partition by po
  order     by startdate
  measures  first(startdate) as startdate, max(enddate) as enddate
  pattern   ( c* n )
  define    c as max(enddate) + 1 >= next(startdate)  
);