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:
It may not be exactly suitable, but this one does only traversal (assuming the list is not clsoed)
create table linkedlist(prevnode int, nextnode int, val int); -- HEAD insert into linkedlist values(null,1,0); insert into linkedlist values(1,2,10); insert into linkedlist values(2,3,20); insert into linkedlist values(3,4,30); insert into linkedlist values(4,5,40); -- TAIL insert into linkedlist values(5,null,50); -- TRAVERSE begin; declare mc cursor for select * from linkedlist order by nextnode; fetch 1 from mc; fetch 1 from mc; ... close mc; commit; which is nothing more than, select * from linkedlist order by nextnode; Regards, Ben K. Developer http://benix.tamu.edu ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
