Module: Legion::Extensions::Neo4j::Runners::Relationships

Includes:
Helpers::Lex, Helpers::Client
Included in:
Client
Defined in:
lib/legion/extensions/neo4j/runners/relationships.rb

Instance Method Summary collapse

Methods included from Helpers::Client

#connection, #execute_cypher

Instance Method Details

#create_relationship(from_id:, to_id:, type:, properties: {}, database: 'neo4j', url: nil, username: nil, password: nil, read_only: false) ⇒ Object

Raises:



28
29
30
31
32
33
34
35
36
37
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 28

def create_relationship(from_id:, to_id:, type:, properties: {}, database: 'neo4j',
                        url: nil, username: nil, password: nil, read_only: false, **)
  raise ReadOnlyError, 'Write operations disabled (read_only mode)' if read_only

  cypher = 'MATCH (a), (b) WHERE elementId(a) = $from_id AND elementId(b) = $to_id ' \
           "CREATE (a)-[r:#{type} $props]->(b) RETURN a, r, b"
  execute_cypher(cypher,
                 parameters: { from_id: from_id, to_id: to_id, props: properties },
                 database: database, url: url, username: username, password: password)
end

#delete_relationship(id:, database: 'neo4j', url: nil, username: nil, password: nil, read_only: false) ⇒ Object

Raises:



48
49
50
51
52
53
54
55
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 48

def delete_relationship(id:, database: 'neo4j', url: nil, username: nil, password: nil,
                        read_only: false, **)
  raise ReadOnlyError, 'Write operations disabled (read_only mode)' if read_only

  execute_cypher('MATCH ()-[r]->() WHERE elementId(r) = $id DELETE r',
                 parameters: { id: id }, database: database,
                 url: url, username: username, password: password)
end

#find_relationships(type:, properties: {}, limit: 25, database: 'neo4j', url: nil, username: nil, password: nil) ⇒ Object 



12
13
14
15
16
17
18
19
20
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 12

def find_relationships(type:, properties: {}, limit: 25, database: 'neo4j',
                       url: nil, username: nil, password: nil, **)
  where_clause = properties.keys.map { |k| "r.#{k} = $#{k}" }.join(' AND ')
  cypher = "MATCH (a)-[r:#{type}]->(b)"
  cypher += " WHERE #{where_clause}" unless where_clause.empty?
  cypher += ' RETURN a, r, b LIMIT $limit'
  execute_cypher(cypher, parameters: properties.merge(limit: limit),
                        database: database, url: url, username: username, password: password)
end

#get_relationship(id:, database: 'neo4j', url: nil, username: nil, password: nil) ⇒ Object 



22
23
24
25
26
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 22

def get_relationship(id:, database: 'neo4j', url: nil, username: nil, password: nil, **)
  execute_cypher('MATCH (a)-[r]->(b) WHERE elementId(r) = $id RETURN a, r, b',
                 parameters: { id: id }, database: database,
                 url: url, username: username, password: password)
end

#list_relationship_types(database: 'neo4j', url: nil, username: nil, password: nil) ⇒ Object 



71
72
73
74
75
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 71

def list_relationship_types(database: 'neo4j', url: nil, username: nil, password: nil, **)
  execute_cypher('CALL db.relationshipTypes() YIELD relationshipType RETURN relationshipType',
                 parameters: {}, database: database,
                 url: url, username: username, password: password)
end

#merge_relationship(from_id:, to_id:, type:, on_create: {}, on_match: {}, database: 'neo4j', url: nil, username: nil, password: nil, read_only: false) ⇒ Object

Raises:



57
58
59
60
61
62
63
64
65
66
67
68
69
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 57

def merge_relationship(from_id:, to_id:, type:, on_create: {}, on_match: {}, database: 'neo4j',
                       url: nil, username: nil, password: nil, read_only: false, **)
  raise ReadOnlyError, 'Write operations disabled (read_only mode)' if read_only

  cypher = 'MATCH (a), (b) WHERE elementId(a) = $from_id AND elementId(b) = $to_id ' \
           "MERGE (a)-[r:#{type}]->(b)"
  cypher += ' ON CREATE SET r += $on_create' unless on_create.empty?
  cypher += ' ON MATCH SET r += $on_match' unless on_match.empty?
  cypher += ' RETURN a, r, b'
  execute_cypher(cypher,
                 parameters: { from_id: from_id, to_id: to_id, on_create: on_create, on_match: on_match },
                 database: database, url: url, username: username, password: password)
end

#neighbors(id:, direction: :both, type: nil, limit: 25, database: 'neo4j', url: nil, username: nil, password: nil) ⇒ Object 



77
78
79
80
81
82
83
84
85
86
87
88
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 77

def neighbors(id:, direction: :both, type: nil, limit: 25, database: 'neo4j',
              url: nil, username: nil, password: nil, **)
  rel = type ? ":#{type}" : ''
  pattern = case direction
            when :outgoing then "(a)-[r#{rel}]->(b)"
            when :incoming then "(a)<-[r#{rel}]-(b)"
            else "(a)-[r#{rel}]-(b)"
            end
  cypher = "MATCH #{pattern} WHERE elementId(a) = $id RETURN b, r LIMIT $limit"
  execute_cypher(cypher, parameters: { id: id, limit: limit },
                        database: database, url: url, username: username, password: password)
end

#shortest_path(from_id:, to_id:, max_depth: 15, database: 'neo4j', url: nil, username: nil, password: nil) ⇒ Object 



90
91
92
93
94
95
96
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 90

def shortest_path(from_id:, to_id:, max_depth: 15, database: 'neo4j',
                  url: nil, username: nil, password: nil, **)
  cypher = 'MATCH (a), (b) WHERE elementId(a) = $from_id AND elementId(b) = $to_id ' \
           "MATCH p = shortestPath((a)-[*..#{max_depth}]-(b)) RETURN p"
  execute_cypher(cypher, parameters: { from_id: from_id, to_id: to_id },
                        database: database, url: url, username: username, password: password)
end

#update_relationship(id:, properties: {}, database: 'neo4j', url: nil, username: nil, password: nil, read_only: false) ⇒ Object

Raises:



39
40
41
42
43
44
45
46
 
# File 'lib/legion/extensions/neo4j/runners/relationships.rb', line 39

def update_relationship(id:, properties: {}, database: 'neo4j', url: nil, username: nil, password: nil,
                        read_only: false, **)
  raise ReadOnlyError, 'Write operations disabled (read_only mode)' if read_only

  execute_cypher('MATCH ()-[r]->() WHERE elementId(r) = $id SET r += $props RETURN r',
                 parameters: { id: id, props: properties }, database: database,
                 url: url, username: username, password: password)
end