CODEWITHSUNDEEP
neo4jduplicatescypheruniquecsv-import
Kilremah Erdne
Kilremah Erdne

Reputation: 11

Extraction of unique nodes from csv in neo4j

In shortest way my problem is below: I need to get from the following csv file

(https...)drive.google.com/file/d/0B-y9nPaqlH6XdXZsYzAwLThacTg/view?usp=sharing

The following data-structure in neo4j (Using cypher import):

https://drive.google.com/file/d/0B-y9nPaqlH6XdlZHM216eDRSX3c/view?usp=sharing

Instead of:

[https://drive.google.com/file/d/0B-y9nPaqlH6XdE9vZ0gyNU1lR0U/view?usp=sharing]

The longer interpretation:

I thought, the solution of my problem is just need to understand to (un)bound elements.

But I tried many times, in many ways (with(out) creating single nodes first, or in empty database):

LOAD CSV with headers FROM "file:///C:/Users/user/Desktop/neo4j help/calling.csv"
AS csvLine

MERGE (u1:Person { number:(csvLine.A), name:(csvLine.name_A)}) MERGE (u2:Person { number:(csvLine.B), name:(csvLine.name_B)})

MERGE (u1:Person { number:(csvLine.A), name:(csvLine.name_A)})-[c:called]->(u2:Person { number:(csvLine.B), name:(csvLine.name_B)})
RETURN u1.name,c,u2.name

I got instead of wondered results just error message:

Can't create u1 with properties or labels here. It already exists in this context

And without „pre-merging“ the nodes, I have the results above (in the pink picture)

What do I need to obtain the wanted result (in the first picture)?

Upvotes: 1

Views: 921

Answers (1)

Christophe Willemsen
Christophe Willemsen

Reputation: 20185

You don't need to redefine the u1 and u2 nodes. Just reuse the identifiers and MERGE the relationship :

LOAD CSV with headers FROM "file:///C:/Users/user/Desktop/neo4j help/calling.csv"
AS csvLine

MERGE (u1:Person { number:(csvLine.A), name:(csvLine.name_A)}) 
MERGE (u2:Person { number:(csvLine.B), name:(csvLine.name_B)})
MERGE (u1)-[c:CALLED]->(u2)
RETURN u1.name,c,u2.name

Nb: I think your images are both the same, and you can post them in your questions, many people will skip your question because they need to open 2 or 3 more browser windows

Upvotes: 2

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