Re: LinkedList

["Ben K." <bkim(at)coe(dot)tamu(dot)edu>]

> 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