图数据库 Neo4j 入门

1 简介

Neo4j 是一个「图数据库」为核心，以自然的连接状态存储和管理数据的工具。它是我们做知识图谱的数据库首选，Neo4j 自带的可视化功能非常方便我们查看数据。

2 安装

这里使用 docker 进行容器化运行，过程非常简单。

docker pull neo4j:5.14.0-community-bullseye

docker run -d --name neo4j --restart=always \
  -p 7474:7474 -p 7687:7687 -v $HOME/data/neo4j:/data \
  neo4j:5.14.0-community-bullseye

# 在浏览器中打开 http://localhost:7474/

3 写入

from neo4j import GraphDatabase, RoutingControl


URI = "neo4j://localhost:7687"
AUTH = ("neo4j", "password")


def add_friend(driver, name, friend_name):
    driver.execute_query(
        "MERGE (a:Person {name: $name}) "
        "MERGE (friend:Person {name: $friend_name}) "
        "MERGE (a)-[:KNOWS]->(friend)",
        name=name, friend_name=friend_name, database_="neo4j",
    )


def print_friends(driver, name):
    records, _, _ = driver.execute_query(
        "MATCH (a:Person)-[:KNOWS]->(friend) WHERE a.name = $name "
        "RETURN friend.name ORDER BY friend.name",
        name=name, database_="neo4j", routing_=RoutingControl.READ,
    )
    for record in records:
        print(record["friend.name"])


with GraphDatabase.driver(URI, auth=AUTH) as driver:
    add_friend(driver, "Arthur", "Guinevere")
    add_friend(driver, "Arthur", "Lancelot")
    add_friend(driver, "Arthur", "Merlin")
    print_friends(driver, "Arthur")

4 查看

# 不带参数查询
MATCH (n) RETURN n LIMIT 25

# 带参数查询
MATCH (n:Person {name: Arthur}) RETURN n LIMIT 25

# 删除所有数据
MATCH (n) DETACH DELETE n

5 参考

• neo4j python-manual/5
• neo4j python-driver