You are correct. I am thinking of the Celko's nested sets is what is not possible.
Dan -----Original Message----- From: Albert Berry Sent: Thursday, March 15, 2012 10:48 AM To: RBASE-L Mailing List Subject: [RBASE-L] - Re: Exploding BOM That's not quite true Dan, you can join one table to another. Select ParentID from Contacts t1, left outer join ChildID from Contacts t2 where t1.ParentID = t2.ParentID. Cannot try it right now - my system just ate my R:Base but I have done this sort of thing in the past. Albert On 15/03/2012 11:33 AM, Dan Goldberg wrote: > The problem is rbase cannot join tables to itself and does not recurse > itself.. That is why you have to use nested cursors. > Dan Goldberg > *From:* Ben Petersen <mailto:[email protected]> > *Sent:* Thursday, March 15, 2012 10:18 AM > *To:* RBASE-L Mailing List <mailto:[email protected]> > *Subject:* [RBASE-L] - Re: Exploding BOM > I looked a little further, this link is much better with examples and > code. > > http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/ > > > > On Thu, Mar 15, 2012 at 9:36 AM, Ben Petersen <[email protected] > <mailto:[email protected]>> wrote: > > Karen, > > Take a look a "nested sets". > > http://en.wikipedia.org/wiki/Nested_set_model > http://www.sqlteam.com/article/more-trees-hierarchies-in-sql > > It takes a minute or two to wrap your head around, but is an > elegant solution (I think) to what you're proposing -- with > unlimited levels. No cursors, but could be write intensive if that > is a concern, though I wouldn't imagine any more than a cursor loop. > > Ben > > > > > > On Thu, Mar 15, 2012 at 8:55 AM, <[email protected] > <mailto:[email protected]>> wrote: > > Dan: That's the way I was going to go, a definite number of > cursors. I feel > better knowing that at least one person did it in that > manner! I'll give it a while > and if no one has code for unlimited levels, then I'll just go > with that. Thanks! > > Karen > > > In a message dated 3/15/2012 10:44:55 AM Central Daylight > Time, [email protected] <mailto:[email protected]> writes: >> >> I use cursors. I just set up for expected level of boms that >> we could possibly imagine using. We only go to a max of 6 >> levels down into the bom so I put in 8 cursor levels to just >> in case and put an error message if it finds something below >> 8 levels so I can add more someday. >> >> I know Rbase does not support celko’s nested boms so I use >> cursors instead. >> >> Dan >> >> >> >
