Python操作Neo4j图数据库的使用完整指南

# 安装驱动
# pip install neo4j
 
from neo4j import GraphDatabase
 
class Neo4jConnection:
    def __init__(self, uri, user, password):
        self.driver = GraphDatabase.driver(uri, auth=(user, password))
 
    def close(self):
        self.driver.close()
 
    def test_connection(self):
        with self.driver.session() as session:
            result = session.run("RETURN 'Connected to Neo4j!' AS message")
            return result.single()["message"]
 
# 连接Neo4j
conn = Neo4jConnection("bolt://localhost:7687", "neo4j", "your_password")
print(conn.test_connection())  # 输出：Connected to Neo4j!
conn.close()

class Neo4jConnection:
    # ... 连接代码同上 ...
 
    def create_friendship(self, person1, person2):
        with self.driver.session() na as session:
            query = (
                "CREATE (p1:Person {name: $person1}) "
                "CREATE (p2:Person {name: $person2}) "
                "CREATE (p1)-[:FRIEND]->(p2)"
            )
            session.run(query, person1=person1, person2=person2)
 
# 创建节点和关系
conn = Neo4jConnection("bolt://localhost:7687", "neo4j", "your_password")
conn.create_friendship("Alice", "Bob")
conn.close()

class Neo4jConnection:
    # ... 连接代码同上 ...
 
    def find_friends(self, name):
        with self.driver.session() as session:
            query = (
                "MATCH (p:Person {name: $name})-[:FRIEND]->(friend) "
                "RETURN friend.name AS friend_name"
            )
            result = session.run(query, name=name)
            return [record["friend_name"] for record in result]
 
# 查询Alice的好友
conn = Neo4jConnection("bolt://localhost:7687", "neo4j", "your_password")
friends = conn.find_friends("Alice")
print(f"Alice's friends: {friends}")  # 输出：Alice's friends: ['Bob']
conn.close()

class Neo4jConnection:
    # ... 连接代码同上 ...
 
    def update_age(self, name, age):
        with self.driver.session() as session:
            query = (
                "MATCH (p:Person {name: $name}) "
                "SET p.age = $age "
                "RETURN p"
            )
            session.run(query, name=name, age=age)
 
    def delete_friendship(self, person1, person2):
        with self.driver.session() as session:
            query = (
                "MATCH (p1:Person {name: $person1})-[:FRIEND]->(p2:Person {name: $person2}) "
                "DELETE r"
            )
            session.run(query, person1=person1, person2=person2)
 
# 更新和删除
conn = Neo4jConnection("bolt://localhost:7687", "neo4j", "your_password")
conn.update_age("Alice", 30)
conn.delete_friendship("Alice", "Bob")
conn.close()

class Neo4jConnection:
    # ... 连接代码同上 ...
 
    def find_second_degree_friends(self, name):
        with self.driver.session() as session:
            query = (
                "MATCH (p:Person {name: $name})-[:FRIEND]->()-[:FRIEND]->(friend) "
                "WHERE friend.name <> $name "
                "RETURN DISTINCT friend.name AS friend_name"
            )
            result = session.run(query, name=name)
            return [record["friend_name"] for record in result]
 
# 查询二级好友
conn = Neo4jConnection("bolt://localhost:7687", "neo4j", "your_password")
second_degree = conn.find_second_degree_friends("Alice")
print(f"Alice's second-degree friends: {second_degree}")
conn.close()