NEO4J

Aplicaciones:

• Whiteboard friendly
• Nice for tree like structures

Arrancar la instancia en local:

> neo4j start

Acceso web al administrador:

Ver en localhost Usuario: neo4j, Password: neo4j

Ficheros en:

cd /usr/local/Cellar/neo4j/3.0.7/libexec

Clientes

• Axios

Búsquedas:

• Obtener 10 nodos ordenados por su id

  MATCH (n:NodeName) RETURN n ORDER BY id(n) LIMIT 10
  

• Calcular la base imponible de una factura

  START invoice=Node(4) MATCH (invoice)-[item:HAS_ITEM]->(p) RETURN invoice.number, sum(item.amount*item.price) AS total
  

• Cambiar la dirección de una RELACIÓN

  MATCH (n)-[r:OLD_REL]->(d) CREATE (n)<-[r2:NEW_REL]-(d) SET r2=r DELETE r
  

• Renombrar un Nodo

  MATCH (n:OldNodeName) REMOVE n:OldNodeName SET n:NewNodeName
  

• Buscar nodos que no tiene etiquetas (labels)

  MATCH (n) WHERE size(labels(n)) = 0 RETURN n
  

• Buscar una relación según su ID (ejemp. ID = 14) y Borrarla

  START r=rel(14) DELETE r
  

• Buscar un nodo según su ID y devolverlo

  START n=node(15) RETURN n
  

• Devolver todos los Nodos

  START n=node(*) RETURN labels(n)[0] AS Etiq, n.name AS Nodo, n.direccion AS Dirección
  

• Eliminar todos los Nodos

  MATCH (n) DETACH DELETE n
  

• Cargar de un CSV y crear o actualizar

  USING PERIODIC COMMIT
  LOAD CSV WITH HEADERS FROM "http://localhost/person_node.csv" as row
  MERGE (p:Person {personId: row.person_id})
  ON CREATE SET p.name = row.name;
  

Creación:

• Crear una propiedad (p.e: ID) "única"

  CREATE CONSTRAINT ON (n:Node) ASSERT n.ID IS UNIQUE
  

Meta-datos:

• Obetener todos las Etiquetas de Nodos de forma separada

  MATCH (n) WITH DISTINCT labels(n) AS labels UNWIND labels AS label RETURN DISTINCT label ORDER BY label
  

basic cypher queries

• Find the unique labels that appear in the database:

  MATCH (n) RETURN DISTINCT labels(n)
  

• Find the unique relationships that appear in the database:

  MATCH (n)-[r]-() RETURN DISTINCT type(r)
  

• Combine the previous two queries to RETURN the unique combinations relationships and labels in the database:

  MATCH (n)-[r]-() RETURN DISTINCT labels(n), type(r)
  

• Find nodes that don't have any relationships:

  START n=node(*)
  MATCH (n)-[r?]-()
  WHERE r IS NULL
  RETURN n
  

• Find all nodes that have a specific property:

  MATCH (n)
  WHERE EXISTS(n.name)
  RETURN n
  

• Find all nodes that have a specific relationship (regardless of the direction of the relationship):

  START n=node(*)
  MATCH (n)-[:SOME_RELATIONSHIP]-()
  RETURN DISTINCT n
  

• Show the nodes and a count of the number of relationships that they have:

  START n=node(*)
  MATCH n-[r]-()
  RETURN n, count(r) AS rel_count
  ORDER BY rel_count DESC
  

• Get a count of all nodes in your graph:

  START n=node(*)
  MATCH n
  RETURN count(n)
  

• To DELETE all nodes in a database (first you have to DELETE all relationships)

  START n=node(*)
  MATCH n-[r]-()
  DELETE r
  

• START n=node(*)

  MATCH n
  DELETE n
  

• A simple query to get nodes of a certain category that MATCH a certain property

  MATCH (n:Person) WHERE n.name="Tim" RETURN n
  

• Poner un nombre de etiqueta a un Nodo que no tiene nombre

  MATCH (n) WHERE size(labels(n)) = 0 SET n:Nuevo_nombre
  

• Búsqueda de toda la cadena de pertenencia

  MATCH (a)-[r:PERTENECE_A*]->(p:Person {name: "Antonio Miguel"}) RETURN r
  

• Devolver todos los Nodos que PERTENECE_A un Nodo dado por su ID

  START n=node(0) MATCH (n)<-[:PERTENECE_A*]-(b) RETURN DISTINCT b
  

• Obtiene los nodos de una cadena de relación y muestra datos en columnas

  START n=node(0) MATCH (d)-[r:PERTENECE_A*]->(n) RETURN DISTINCT labels(d)[0] as Nodo, d, type(r[0])
  

• Buscar un Nodo cuya propiedad coincida con un patron regular

  START n = node(*) WHERE n.name =~ '.*toni.*' RETURN n.name, n
  

• Obtiene el ID de un Nodo

  START n = node(*) WHERE n.name =~ '.*toni.*' RETURN ID(n) AS ID,n AS Node