> If I use the value of the hierarchy column in a query I can get all
> the rows that a given row is an descendant of. (SELECT * FROM items
> WHERE itm_id IN (1,31,68,97), for example. However, I need the rows
> to be in the correct order, ie the root node first, child second,
> grandchild third etc. I'm guessing the order can be set with an ORDER
> BY, but I've only ever used ORDER BY to order by ascending or
> descending order of a single column. Is there a way to retrieve the
> rows explicitly in the order they are listed in the hierarchy array?
If you've got the intarray contrib module installed, you can use
idx(array[1,31,68,97], i)