Scott, Thanks for your reply, I tried what you said, worked around a few things but I am still stuck. The main reason is I didn't do an adequate job of explaining the situation. The table implements many linked lists and I want to traverse one of them given the end of the list.
Say the table contains h | v | j 1 0 100 3 1 300 5 3 500 7 5 700 2 0 200 4 2 400 6 4 600 8 6 800 If I specify t.h = 8 I want to traverse the even part of the table If I specify t.h = 7 I want to traverse the odd part of the table If you can send me to a book to read I am willing Thanks -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Scott Marlowe Sent: Wednesday, April 26, 2006 8:59 AM To: Ray Madigan Cc: pgsql-sql@postgresql.org Subject: Re: [SQL] LinkedList On Wed, 2006-04-26 at 11:09, Ray Madigan wrote: > I have a table that I created that implements a linked list. I am not an > expert SQL developer and was wondering if there are known ways to traverse > the linked lists. Any information that can point me in the direction to > figure this out would be appreciated. The table contains many linked lists > based upon the head of the list and I need to extract all of the nodes that > make up a list. The lists are simple with a item and a link to the history > item so it goes kind of like: > > 1, 0 > 3, 1 > 7, 3 > 9, 7 > ... > > Any suggestions would be helpful, or I will have to implement the table > differently. You should be able to do this with a fairly simple self-join... select a.id, b.aid, a.field1, b.field1 from mytable a join mytable b on (a.id=b.aid) Or something like that. ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
