Optimise Cypher query

[peetsees]

Hi all,

I am quite new to Neo4j and cypher queries and it would be great if you could help me.

I have the following nodes:

• Transaction (tx)

• Output (output)

with the following relations:

• Incoming (in)

• Outgoing (out)

a Transaction creates 1-n outputs which can be used as inputs for other transactions.

I want to check, which outputs and transactions are children of a target transaction (means, created inputs for the target transaction.) This query checks 2 hops back:

MATCH path= (roottx:tx {txid:'266160772'})<-[:in|:out]-(output0:output)<-[:in|:out]-(subtx:tx)<-[:in|:out]-(output1:output)<-[:in|:out]-(subtx1:tx)<-[:in|:out]-(output2:output)

RETURN path

I have the aim, that the query should be flexible - means it should be able to check more hops back.

I think there is definitely a better way than extending the query.

I already had a look in APOC methods - but I was not able to find the right one.

Thanks a Lot for your help and your time!

[Cobra]

Hello @peetsees and welcome to the Ne4j community

You should have a look at this:
https://neo4j.com/docs/cypher-manual/current/clauses/match/#varlength-rels

Regards,
Cobra

[peetsees]

@Cobra: Thanks a lot! I had a look in this chapter, but somehow I was not able to handle the outputs and transactions....

Now I managed it!

MATCH path= (roottx:tx {txid:'266160772'})<-[:in|:out*1..6]-(tx:tx)
RETURN path

basically delivered the same result as my query in the original post above!

Thanks for your help!

[Cobra]

Nice, I'm happy to hear this

[peetsees]

On additional idea came to my mind, which I am trying to find a query:

It would be great to see the interactions of transactions. Means, I would like to see only transactions in my graph, without he outputs of the transactions (see picture above).

I tried to formulate the query like this:

MATCH  (roottx:tx {txid:'266160772'})<-[:in|:out*1..6]-(tx:tx)
RETURN tx

But then the relationsships are gone:

Is it possible, to replace the OUTPUT nodes, but still create a connection between the TRANSACTION nodes?

Thanks for your help!

[ofer_bar]

You can simply return only the nodes that you want:

MATCH path= (roottx:tx {txid:'266160772'})<-[:in|:out*1..6]-(tx:tx)
RETURN tx

[Cobra]

Your orange nodes are not directly connected to each other right? There are blue node between them?

[peetsees]

Yes.

Transactions (orange nodes) are connected with outputs (blue nodes) via IN or OUT relation.

So, I would need to replace the IN-OUTPUT-OUT part between the transactions with a kind of dummy relation (only in the query result).

[Cobra]

You will have to create this "dummy" relation if you want to display it