Question

Ik have a table with route information in random order, like this:

from    to      street
----------------------------------
92      91      Lange Poten
100     104     Bagijnestraat
85      79      Korte Poten
91      85      Plein
79      100     Bezuidenhoutseweg

I’m trying to find a method to sort it using the route information, where the to column of the current row matches with the from column of the next row. In the example, the order I want is:

from    to      street
----------------------------------
92      91      Lange Poten
91      85      Plein
85      79      Korte Poten
79      100     Bezuidenhoutseweg
100     104     Bagijnestraat

A simple ORDER BY on the from or to column doesn’t work because a numerical order isn’t the right one. I’m trying to find a method using SQL or Excel.

SQL Fiddle here: http://sqlfiddle.com/#!2/9ebbb

Answer 1

This works in oracle

select a.*
from route  a
start with a.rowid = (select min(rowid) from route )
connect by prior a.t = a.f;