Introduction to Querying Property Graphs

We're finally ready to query a real graph database. We'll query Neo4j with Cypher.

We've got our graph database (Neo4j) running and a connection to the database (Bolt) set up. We've also created our property graph service API (PropertyGraph) and have added in the query helper cypher!/1 for sending Cypher queries.

Now we just want to get down to the business of querying it.

What we’ll cover

We’ll focus here on a couple of simple applications by way of getting acquainted with Neo4j property graphs using Elixir. We’ll start off with some basics for creating and querying nodes, relationships, and paths and provide a rudimentary test query library.

We’ll then create a simple graph—the book graph—and see how this is implemented in Cypher. And then, we’ll create another larger graph—the ARPANET graph—to look at an example of a real network.

Parameter passing in queries is an important capability. We’ll cover that, extend our query API to support parameters, and also show some examples of this in action.

We’ll round this out with some general remarks on property graphs and schemas, and we’ll anticipate the RDF schemas that we’ll meet later.