Thanks Andrés! Couple of random extensions to the thoughts above:
- To be consistent, perhaps for "optional matches", the results could always include a row where that optional match was ignored. That way, "Elizabeth, <null>" wouldn't be an inconsistency; *every* first-degree friend would have an "[friend], <null>" row. - And perhaps *that* row could be the one that has the full node data, and every subsequent row for the second optional match would just reference the URL/ID of the first-degree node. After chewing on this a lot more, though, I've realized that what I really want in this scenario is not tabular data, but a real subgraph. Hence my email just now. =) Aseem On Thu, Aug 25, 2011 at 1:34 PM, Andres Taylor < andres.tay...@neotechnology.com> wrote: > Good and valid requests, Aseem. > > Consider them heard. We'll see how soon we can get it to you. > > Andrés > > On Thu, Aug 25, 2011 at 12:57 PM, Aseem Kishore <aseem.kish...@gmail.com > >wrote: > > > Man, I am loving Cypher. Thanks so much guys for introducing it. I'm a > bit > > stuck on one query, though, and I wanted to ask for help. I think the > > reasons I'm stuck are related to the two feature requests I made > yesterday > > (optional matches, and returning IDs). > > > > I want to fetch first- and second-degree friends in one query, in a way > > that > > preserves the first-degree friend(s) for each second-degree friends. > Assume > > an asymmetrical friendship model, like Twitter's following, because that > > makes things a bit easier. > > > > Here's a simple transitive example: > > > > - Alice follows Bob and Carol. > > - Bob follows Carol and Dave. > > - Carol follows Dave and Alice. > > > > > > I want to fetch Alice's first-degree friends (Bob and Carol) and each of > > their first-degree friends ((Carol and Dave) for Bob, and (Dave and > Alice) > > for Carol). This example is easy enough: > > > > START zero=(Alice) > > MATCH (zero) -[:FOLLOWS]-> (first) -[:FOLLOWS]-> (second) > > RETURN first, second > > > > > > I expect to get back results like: > > > > - Bob, Carol > > - Bob, Dave > > - Carol, Dave > > - Carol, Alice > > > > > > This is great because I can get Alice's first-degree friends by > > unique()'ing > > the first column, for each person, I know their second-degree friends via > > the second column. > > > > But this doesn't work if any of my first-degree friends don't follow > > anyone. > > For that, it would be great if I could specify that the second part of > that > > match was "optional", and I'd get back a row like this in that case: > > > > - Elizabeth, <null> > > > > If I'm returning nodes, it also duplicates a ton of info: each > first-degree > > friend's info is returned in full for each of their friends. Maybe > there's > > no way around that, but this is also where I would find it convenient to > be > > able to return IDs somehow for all but one of the results. > > > > Just thinking out loud here, but I'd greatly appreciate any feedback or > > ideas for this scenario. Thanks much! > > > > Aseem > > _______________________________________________ > > Neo4j mailing list > > User@lists.neo4j.org > > https://lists.neo4j.org/mailman/listinfo/user > > > _______________________________________________ > Neo4j mailing list > User@lists.neo4j.org > https://lists.neo4j.org/mailman/listinfo/user > _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
