Neo4j has a csv import tool that makes importing large datasets pretty easy, especially if you happen to be exporting data out of postgres with the COPY command. We’re going to take a quick look at importing with the imdb movie dataset (docs here: http://www.imdb.com/interfaces).

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There is more than one way to import data into Neo4j, like the cypher command LOAD CSV which is recommended for medium sized datasets up to 10M records. This is a little smaller than our movie dataset, so the one we will look at uses the command line neo4j-admin import, recommended by Neo4j for huge datasets.

This is the example command we will be using:

neo4j-admin import \
  --nodes name.basics.csv \
  --nodes title.basics.csv \
  --relationships title.principals.csv \
  --ignore-missing-nodes

The csv files need to be formatted in a particular way to correctly create nodes and relationships, and the ignore-missing-nodes needs to be added so the importer ignores relationships with no nodes instead of throwing errors (them imdb dataset we are using references a few missing nodes)

Nodes: <primary_key_name>:ID,attr1,attr2,:LABEL

  • <primary_key_name>:Id is the id of our node, can be any id name like movieId:ID or personId:ID
  • :LABEL is any label attached
  • attributes can be added in between :START_ID and :END_ID

Relationships: :START_ID,attr1,attr2,:END_ID,:TYPE

  • :START_ID and :END_ID refer to the ids of the nodes in the relationship
  • :TYPE is the relationship type
  • attributes can be added in between :START_ID and :END_ID

For our imdb data we are going to pull 3 files:

  • https://datasets.imdbws.com/name.basics.tsv.gz, actor name to id
  • https://datasets.imdbws.com/title.basics.tsv.gz, movie name to id
  • https://datasets.imdbws.com/title.principals.tsv.gz, movie id to actor ids (the cast)

The files are tab seperated and gzipped, so we’ll go through the motions of quickly changing them over to a csv format.

For the actors, it will roughly look like this:

require 'open-uri'

url          = 'https://datasets.imdbws.com/name.basics.tsv.gz'
csv_filepath = File.join(Dir.pwd, 'name.basics.csv')
csv_headers  = "personId:ID,name,:LABEL \n"

zipped   = open(url)
unzipped = Zlib::GzipReader.new(zipped)

File.open(csv_filepath, 'w') do |csv_file|
  csv_file.write(csv_headers)

  unzipped.each_line do |line|
    values   = line.strip.split("\t")
    personID = values[0]
    name     = values[1]

    csv_file.write("#{personID},#{name},Actor \n")
  end
end

Movies will mostly look the same, except we are only interested in titleType of movies (skipping episodes, shorts, …):

require 'open-uri'

url          = 'https://datasets.imdbws.com/title.basics.tsv.gz'
csv_filepath = File.join(Dir.pwd, 'title.basics.csv')
csv_headers  = "movieId:ID,name,:LABEL \n"

zipped   = open(url)
unzipped = Zlib::GzipReader.new(zipped)

File.open(csv_filepath, 'w') do |csv_file|
  csv_file.write(csv_headers)

  unzipped.each_line do |line|
    values   = line.strip.split("\t")
    personID = values[0]
    name     = values[2]

    csv_file.write("#{movieID},#{name},Movie \n") unless values[1] == 'movie'
  end
end

The relationships:

url          = 'https://datasets.imdbws.com/title.principals.tsv.gz'
csv_filepath = File.join(Dir.pwd, 'title.principals.csv')
csv_headers  = ":START_ID,:END_ID,:TYPE \n"

zipped   = open(url)
unzipped = Zlib::GzipReader.new(zipped)

File.open(csv_filepath, 'w') do |csv_file|
  csv_file.write(csv_headers)

  unzipped.each_line do |line|
    values  = line.strip.split("\t")
    movieID = values[0]
    cast    = values[1].split(",")

    cast.each_with_object('') do |actorID, str|
      csv_file.write("#{actorID},#{imdbID},ACTED_IN \n")
    end
  end
end

Now that we have the csv data for all our movie and actors, we just pass them to the command from the beginning and we are ready to play with some graph data for movies!