Get the paths from a database of points in sql

Question

Consider that I have a table of points, each point has 2 coordinates. For example:

Source       |       Destination 
1            |       2
2            |            


        

Answer 1

with recursive
  points(src, dst) as (values(1,2),(3,7),(2,3),(5,7),(9,12)),
  result as (
    select src, dst, array[src,dst] as point, 1 as n
    from points p1
    where not exists(select * from points p2 where p2.dst = p1.src)
    union all
    select result.src, points.dst, array[points.src, points.dst], n+1
    from result join points on (result.dst = points.src)
  )
select array_agg(point order by n) from result group by src;