[Neo] Relation properties

Rick Bullotta rick.bullotta at burningskysoftware.com
Fri Jan 29 16:48:34 CET 2010


Why do you need to set your own ID's?  You can use the relationship's
built-in as your index key (it is guaranteed to be unique) and
getRelationshipByID to retrieve the relationship.  You'd need to very
slightly extend the LuceneIndex stuff to deal with relationships, but it
shouldn't be difficult.

-----Original Message-----
From: user-bounces at lists.neo4j.org [mailto:user-bounces at lists.neo4j.org] On
Behalf Of Anton Popov
Sent: Friday, January 29, 2010 9:31 AM
To: Neo user discussions
Subject: Re: [Neo] Relation properties

And as far as I can see there is no way to set my own id'es for Relations?
Only Nodes has such functionality - am I right?

---------- Forwarded message ----------
From: Anton Popov <popov.UA.work at gmail.com>
Date: 2010/1/29
Subject: Re: [Neo] Relation properties
To: Neo user discussions <user at lists.neo4j.org>


Hello Mattias,

Got it. Thanks.
Is there any RoadMap available?

2010/1/29 Mattias Persson <mattias at neotechnology.com>

Unfortunately you cannot index Relationships, but it's a (frquently
> requested) feature we're planning to add.
>
> 2010/1/29 Anton Popov <popov.UA.work at gmail.com>:
> > Hello everybody,
> >
> > A related question is can I index both Nodes & Relations?
> > As I can see LuceneIndexBatchInserter.index( long node, String key,
> Object
> > value ) applies for Nodes only.
> >
> > 2010/1/28 Mattias Persson <mattias at neotechnology.com>
> >
> >> Not at all, you're not the first one to overlook that inheritance!
> >>
> >> 2010/1/28, Anton Popov <popov.UA.work at gmail.com>:
> >> > Thanks for a quick answer, Mattias.
> >> >
> >> > Sorry for a stupid questions, just haven't noticed the inheritance of
> >> > Relationship interface.
> >> >
> >> > On 28 January 2010 19:43, Mattias Persson <mattias at neotechnology.com>
> >> wrote:
> >> >
> >> >> Relationship has all the property methods, just like Node... they're
> >> >> actually on PropertyContainer (a common super interface to Node and
> >> >> Relationship) see
> >> >> http://api.neo4j.org/current/org/neo4j/graphdb/Relationship.html and
> >> >>
> http://api.neo4j.org/current/org/neo4j/graphdb/PropertyContainer.html
> >> >> for more information.
> >> >>
> >> >> So to manage the cost in a dijkstra algorithm you can use whatever
> >> >> property key, f.ex. "weight", like this:
> >> >>
> >> >>    Relationship rel = ... // any relationship
> >> >>    rel.setProperty( "weight", 4 );
> >> >>
> >> >> And if you're using the Dijkstra algorithms in the
"neo4j-graph-algo"
> >> >> component, http://components.neo4j.org/neo4j-graph-algo/ , you can
> >> >> instantiate it with a CostEvaluator instance something like this:
> >> >>
> >> >>    new CostEvaluator<Integer>()
> >> >>    {
> >> >>        CostType getCost( Relationship relationship, boolean
backwards
> )
> >> >>        {
> >> >>            / TODO Handle backwards flag?
> >> >>            return ( Integer ) relationship.getProperty( "weight", 1
> );
> >> >>        }
> >> >>    }
> >> >>
> >> >> ...and pass it to your Dijkstra algo instance.
> >> >>
> >> >> Is this what you were looking for?
> >> >>
> >> >> 2010/1/28 Anton Popov <popov.UA.work at gmail.com>:
> >> >> > Hello everyone,
> >> >> >
> >> >> > Is there any possibility to assign properties to Relations?
> >> >> > The matter is I want to try Dijkstra algorithm performance on some
> >> >> weighted
> >> >> > directed graph and don't know where to put weight actually...
> >> >> >
> >> >> > --
> >> >> > Best regards,
> >> >> > Popov Anton
> >> >> > _______________________________________________
> >> >> > Neo mailing list
> >> >> > User at lists.neo4j.org
> >> >> > https://lists.neo4j.org/mailman/listinfo/user
> >> >> >
> >> >>
> >> >>
> >> >>
> >> >> --
> >> >> Mattias Persson, [mattias at neotechnology.com]
> >> >> Neo Technology, www.neotechnology.com
> >> >> _______________________________________________
> >> >> Neo mailing list
> >> >> User at lists.neo4j.org
> >> >> https://lists.neo4j.org/mailman/listinfo/user
> >> >>
> >> >
> >> >
> >> >
> >> > --
> >> > Best regards,
> >> > Popov Anton
> >> > _______________________________________________
> >> > Neo mailing list
> >> > User at lists.neo4j.org
> >> > https://lists.neo4j.org/mailman/listinfo/user
> >> >
> >>
> >>
> >> --
> >> Mattias Persson, [mattias at neotechnology.com]
> >> Neo Technology, www.neotechnology.com
> >> _______________________________________________
> >> Neo mailing list
> >> User at lists.neo4j.org
> >> https://lists.neo4j.org/mailman/listinfo/user
> >>
> >
> >
> >
> > --
> > Best regards,
> > Popov Anton
> > _______________________________________________
> > Neo mailing list
> > User at lists.neo4j.org
> > https://lists.neo4j.org/mailman/listinfo/user
> >
>
>
>
> --
> Mattias Persson, [mattias at neotechnology.com]
> Neo Technology, www.neotechnology.com
> _______________________________________________
> Neo mailing list
> User at lists.neo4j.org
> https://lists.neo4j.org/mailman/listinfo/user
>



-- 
Best regards,
Popov Anton



-- 
Best regards,
Popov Anton
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