LOAD CSV Data Import

Who this course is for

This lab is for anyone who wants to learn the LOAD CSV clause itself, in depth and by doing: developers who prefer working in code over a visual tool, analysts who receive data as CSV exports and need it queryable as a graph, and learners who have finished the CypheriFull definition for Cypher (opens in a new tab)Neo4j's implementation of GQL, the ISO standard query language for graph databases. It is declarative: you describe the pattern to find, and the database decides how to find it. basics and want a concrete project. You should be comfortable with the basic Cypher taught in Neo4j Fundamentals and Cypher Fundamentals, since the import patternsiFull definition for pattern (opens in a new tab)A graph structure written in Cypher, such as a node joined to another node by a relationship. here combine LOAD CSV with MATCH, MERGE, and WHERE. The lab is short and entirely hands-on: you spend the 40 minutes writing and running import statements against your own database.

What you'll do

You will start with an empty database and finish with a connected movie graph, built entirely with CypheriFull definition for Cypher (opens in a new tab)Neo4j's implementation of GQL, the ISO standard query language for graph databases. It is declarative: you describe the pattern to find, and the database decides how to find it. you wrote yourself. First you will learn how LOAD CSV actually works: how it fetches a file from a URL, how WITH HEADERS turns each row into a map keyed by column name, and how Neo4j processes the file one row at a time. You will then import Person and Movie nodesiFull definition for node (opens in a new tab)A vertex in a graph. In a property graph it can carry labels and properties. with correctly typed propertiesiFull definition for property (opens in a new tab)A named value stored on a node or a relationship. using conversion functions such as toInteger() and toFloat(), and use MATCH to find nodes by identifier and create the relationshipsiFull definition for relationship (opens in a new tab)A named, directed connection between two nodes. Every relationship has a type, a start node and an end node. between them.

The second half of the lab is about robustness. You will make your import idempotent, replacing CREATE with MERGE so re-running a statement cannot produce duplicates, filter out rows with missing values with WHERE, supply defaults with coalesce(), and batch large imports. The lab closes with a final challenge: importing a complete dataset in a single, end-to-end pipeline.

Where to go next

The patternsiFull definition for pattern (opens in a new tab)A graph structure written in Cypher, such as a node joined to another node by a relationship. in this lab scale directly to your own data: swap the movie files for your CSV exports and the same statements apply. Importing CSV data into Neo4j goes further with Cypher-based importing, covering list propertiesiFull definition for property (opens in a new tab)A named value stored on a node or a relationship., adding labelsiFull definition for label (opens in a new tab)A tag on a node that groups it with other nodes of the same kind. A node can carry more than one. from data, and managing transactionsiFull definition for transaction (opens in a new tab)A unit of work that either succeeds in full or leaves no trace. with CALL { ... } IN TRANSACTIONS, while Importing Data Fundamentals introduces the Neo4j Data ImporteriFull definition for Data Importer (opens in a new tab)The Neo4j tool for loading CSV files into a graph by mapping their columns onto nodes and relationships., the visual alternative. LOAD CSV also appears on the Neo4j Certified Professional exam, so the practice you get here counts directly toward earning that certification.