NAME

Neo4j::Bolt - query Neo4j using Bolt protocol

SYNOPSIS

use Neo4j::Bolt;
$cxn = Neo4j::Bolt->connect("bolt://localhost:7687");
$stream = $cxn->run_query(
  "MATCH (a) RETURN head(labels(a)) as lbl, count(a) as ct",
  {} # parameter hash required
);
@names = $stream->fieldnames;
while ( my @row = $stream->fetch_next ) {
  print "For label '$row[0]' there are $row[1] nodes.\n";
}
$stream = $cxn->run_query(
  "MATCH (a) RETURN labels(a) as lbls, count(a) as ct",
  {} # parameter hash required
);
while ( my @row = $stream->fetch_next ) {
  print "For label set [".join(',',@{$row[0]})."] there are $row[1] nodes.\n";
}

DESCRIPTION

Neo4j::Bolt is a Perl wrapper around Chris Leishmann's excellent libneo4j-client library implementing the Neo4j Bolt network protocol. It uses Ingy's Inline::C to do all the hard XS work.

Return Types

Neo4j::Bolt::ResultStream returns rows resulting from queries made via a Neo4j::Bolt::Cxn. These rows are simple arrays of scalars and/or references. These represent Neo4j types according to the following:

Neo4j type       Perl representation
----- ----       ---- --------------
Null             undef
Bool             JSON::PP::Boolean (acts like 0 or 1)
Int              scalar
Float            scalar
String           scalar
Bytes            scalar
List             arrayref
Map              hashref
Node             hashref  (Neo4j::Bolt::Node)
Relationship     hashref  (Neo4j::Bolt::Relationship)
Path             arrayref (Neo4j::Bolt::Path)

Nodes, Relationships and Paths are represented in the following formats:

# Node:
bless {
  id => $node_id,  labels => [$label1, $label2, ...],
  properties => {prop1 => $value1, prop2 => $value2, ...}
}, 'Neo4j::Bolt::Node'

# Relationship:
bless {
  id => $reln_id,  type => $reln_type,
  start => $start_node_id,  end => $end_node_id,
  properties => {prop1 => $value1, prop2 => $value2, ...}
}, 'Neo4j::Bolt::Relationship'

# Path:
bless [
  $node1, $reln12, $node2, $reln23, $node3, ...
], 'Neo4j::Bolt::Path'

METHODS

connect($url), connect_tls($url,$tls_hash)

Class method, connect to Neo4j server. The URL scheme must be 'bolt', as in

$url = 'bolt://localhost:7687';

Returns object of type Neo4j::Bolt::Cxn, which accepts Cypher queries and returns a Neo4j::Bolt::ResultStream.

To connect by SSL/TLS, use connect_tls, with a hashref with keys as follows

ca_dir => <path/to/dir/of/CAs
ca_file => <path/to/file/of/CAs
pk_file => <path/to/private/key.pm
pk_pass => <private/key.pm passphrase>

Example:

$cxn = Neo4j::Bolt->connect_tls('bolt://boogaloo-dudes.us:7687', { ca_cert => '/etc/ssl/cert.pem' });

When neither ca_dir nor ca_file are specified, an attempt will be made to use the default trust store instead. This requires IO::Socket::SSL or Mozilla::CA to be installed.

SEE ALSO

Neo4j::Bolt::Cxn, Neo4j::Bolt::ResultStream.

AUTHOR

Mark A. Jensen
CPAN: MAJENSEN
majensen -at- cpan -dot- org

CONTRIBUTORS

Arne Johannessen (@johannessen)

LICENSE

This software is Copyright (c) 2019-2020 by Mark A. Jensen.

This is free software, licensed under:

The Apache License, Version 2.0, January 2004