Neo4j是一個(gè)高性能的NoSQL圖形數(shù)據(jù)庫,它具有成熟數(shù)據(jù)庫的所有特性。在Neo4j中處理復(fù)雜關(guān)系,可以使用以下方法:
MATCH
、WHERE
、CREATE
、UPDATE
、DELETE
等。示例:查詢兩個(gè)節(jié)點(diǎn)之間的所有路徑
MATCH (a)-[*]->(b) WHERE a.name = "A" AND b.name = "B" RETURN a, b
示例(Python):創(chuàng)建一個(gè)節(jié)點(diǎn)并添加關(guān)系
from neo4j import GraphDatabase
class Neo4jDB:
def __init__(self, uri, user, password):
self._driver = GraphDatabase.driver(uri, auth=(user, password))
def close(self):
if self._driver:
self._driver.close()
def create_node(self, label, properties):
with self._driver.session() as session:
result = session.write_transaction(self._create_node_tx, label, properties)
return result
@staticmethod
def _create_node_tx(tx, label, properties):
query = f"CREATE (n:{label} $properties) RETURN id(n)"
result = tx.run(query, properties=properties)
record = result.single()
return record["id(n)"] if record else None
# 使用示例
db = Neo4jDB("bolt://localhost:7687", "username", "password")
db.create_node("Person", {"name": "John", "age": 30})
db.close()
示例:使用APOC計(jì)算兩個(gè)節(jié)點(diǎn)之間的最短路徑
CALL apoc.path.expandConfig({
startNodeLabel: "Person",
endNodeLabel: "Person",
relationshipTypes: ["KNOWS"],
minLevel: 2,
maxLevel: 3
}) YIELD path
RETURN path
示例:計(jì)算節(jié)點(diǎn)的中心性
MATCH (n)
WITH n, size((n)--()) AS degree
RETURN n, degree
ORDER BY degree DESC
通過以上方法,可以靈活地處理Neo4j中的復(fù)雜關(guān)系。在實(shí)際應(yīng)用中,可以根據(jù)需求選擇合適的方法進(jìn)行處理。