Graph relations in Neo4j – simple load example

Graph of first load test of Neo4j
Basic load example of a handful of relationships.

In preparation for a post about doing graph analytics in Neo4j (paralleling SPARQLverse from this earlier post), I had to learn to load text/CSV data into Neo.  This post just shows the steps I took to load nodes and then establish edges/relationships in the database.

My head hurt trying to find a simple example of loading the data I had used in my earlier example but this was because I was new to the Cypher language.  I was getting really hung up on previewing the data in the Neo4j visualiser and finding that all my nodes had only ID numbers was really confusing me.  I had thought it wasn’t loading my name properties or something when it was really just a visualisation setting (more on that another time).  Anyway, enough distractions…

Graph Data File – Simple Graph Relations Example

I took my earlier sample data and dumbed it down to fit the normal paradigm of Neo4j – separate nodes and edges load files.  I appreciated working with triples before as I didn’t have to pre-load all the nodes first, but that’s also a story for another day.

First, the nodes file looked like the following.  Note, I thought I had to add the ID though I didn’t end up using it after all:

The second file was simply a list of “source” and “target” names – the graph relations – where the first person had the second person for a friend.  (We handle them as unidirectional in this example.)

Graph of first load test of Neo4j
Basic load example of a handful of relationships.

Loading CSV Relationships into Neo4j

To get the data into Neo4j I had to run two commands.  But first I run a sort of “delete all” as I was doing lots of testing:

Then load all the nodes, assigning each one to a Person entity and grabbing only the name property from the CSV:

And finally, load the edges/relationships to map persons -> to persons via a has_friend relationship:

The resulting load will say something like:

Created 57 relationships, returned 0 rows in 46 ms

More on exploring and analysing this in a future post.  Tweet it or comment if you are interested in more along this line.  Thanks for reading!


© Tyler Mitchell / Spatialguru.com