Book Image

Graph Data Processing with Cypher

By : Ravindranatha Anthapu
Book Image

Graph Data Processing with Cypher

By: Ravindranatha Anthapu

Overview of this book

While it is easy to learn and understand the Cypher declarative language for querying graph databases, it can be very difficult to master it. As graph databases are becoming more mainstream, there is a dearth of content and guidance for developers to leverage database capabilities fully. This book fills the information gap by describing graph traversal patterns in a simple and readable way. This book provides a guided tour of Cypher from understanding the syntax, building a graph data model, and loading the data into graphs to building queries and profiling the queries for best performance. It introduces APOC utilities that can augment Cypher queries to build complex queries. You’ll also be introduced to visualization tools such as Bloom to get the most out of the graph when presenting the results to the end users. After having worked through this book, you’ll have become a seasoned Cypher query developer with a good understanding of the query language and how to use it for the best performance.
Table of Contents (18 chapters)
1
Part 1: Cypher Introduction
4
Part 2: Working with Cypher
9
Part 3: Advanced Cypher Concepts

Loading data with LOAD CSV

LOAD CSV can be used to load the data from the following:

  • Local filesystem on a server: The files have to be in the import directory of the server. LOAD CSV cannot access random locations.
  • From a URL: It is possible to load the data from any URL that is accessible from the server.

Note

Remember that LOAD CSV is the command issued by the client to the server. If it is a URL, it should be accessible from the server, as the server will try to download the CSV content from the URL and process the next steps.

We will take a look at some LOAD CSV usage examples in this section.

When the server processes the CSV file, each row is converted into a MAP or LIST type depending on how the command is issued.

LOAD CSV without headers

When we use the LOAD CSV command without a header option, then each row is mapped as a list. The screenshot here shows how this would look:

Figure 3.2 – LOAD CSV from the browser...