Neo4j 简介

安装 Neo4j Python 驱动的命令

1pip install neo4j

导入 Neo4j 模块

1from neo4j import GraphDatabase

连接到 Neo4j 实例

1connection_uri = ""  # Neo4j 实例的连接 URI（Bolt URL）
2username = ""          # Neo4j 账户用户名
3password = ""          # Neo4j 账户密码
4driver = GraphDatabase.driver(connection_uri, auth=(username, password))

开启会话以执行查询

1with driver.session() as session:
2    result = session.run(query)
3driver.close()

在 Neo4j 中创建节点

1CREATE (EmperorShahJahan:Person {name: 'Shah Jahan', aged: '74'})

在 Neo4j 中创建另一个节点

1CREATE (TajMahal:Monument {name: "Taj Mahal"})

如果这两个实体之间已存在类型为 RELATION 的关系，则会新增一条相同的关系，导致出现重复

1CREATE (TajMahal)-[:RELATION {name: 'BUILT_BY', year: 1643}]->(EmperorShahJahan)

如果两个节点已存在，则不会创建新节点

1MERGE (EmperorShahJahan:Person {name: 'Shah Jahan', aged: '74'})
2MERGE (TajMahal:Monument {name: "Taj Mahal"})

MERGE 可避免在相同节点间创建重复的关系

1MERGE (TajMahal)-[:RELATION {name: 'BUILT_BY', year: 1643}]->(EmperorShahJahan)

代码示例

1MATCH (TajMahal:Monument {name: 'Taj Mahal'}), (EmperorShahJahan:Person {name: 'Shah Jahan'})
2MERGE (TajMahal)-[:RELATION {name: 'BUILT_BY', year: 1643}]->(EmperorShahJahan)

Cypher 查询：获取 Neo4j 实例中所有实体及关系

1MATCH (n)-[r]->(m)
2RETURN n, r, m

Cypher 查询：查找特定实体及其与其他实体的关系

1MATCH (n {name: 'Taj Mahal'})-[r]->(m)
2RETURN n, r, m

Cypher 查询：查找并删除特定关系

1MATCH ()-[r:RELATION {name: 'BUILT_BY'}]->()
2DELETE r

Cypher 查询：删除节点及其关联的所有关系

1MATCH (n:Person {name: 'Shah Jahan'})
2DETACH DELETE n

Cypher 查询：删除所有关系

1MATCH ()-[r]->()
2DELETE r

Cypher 查询：删除所有节点和关系

1MATCH (n)
2DETACH DELETE n