Create string from array

Question

I have a table in PostgreSQL that contains:

id   name   arrayofparents
1     First
2     Second      {1}
3     Second_Sec  {1,2}
4     Third       {1,2,3}
5          


        

Answer 1

If you only want direct parents (not grandparents) then something like this should work:

SELECT c.id, c.name, string_agg(p.name, '->') AS parentnames
FROM yourtable AS c
  LEFT JOIN yourtable AS p ON p.id = ANY c.parents
GROUP BY c.id, c.name