python操作图数据库neo4j

• 两种方式：

1、执行CQL ( cypher ) 语句

2、通过操作python变量，达到操作neo4j的目的

• 个人觉得第二部分最好：

优点：符合python的习惯，写着感觉顺畅，其实可以完全不会CQL也能写

缺点：代码长度比纯CQL要长，熟悉CQL的人可能会感觉拖沓

1、（用neo4j模块）执行CQL ( cypher ) 语句

• 官网文档：https://neo4j.com/docs/api/python-driver/1.7/#api-documentation

• CQL(cypher)语法快查：https://neo4j.com/docs/cypher-refcard/current/

官方示例1:
from neo4j import GraphDatabase

driver = GraphDatabase.driver("bolt://localhost:7687", auth=("neo4j", "password"))

def add_friend(tx, name, friend_name):
    tx.run("MERGE (a:Person {name: $name}) "
           "MERGE (a)-[:KNOWS]->(friend:Person {name: $friend_name})",
           name=name, friend_name=friend_name)

def print_friends(tx, name):
    for record in tx.run("MATCH (a:Person)-[:KNOWS]->(friend) WHERE a.name = $name "
                         "RETURN friend.name ORDER BY friend.name", name=name):
        print(record["friend.name"])

with driver.session() as session:
    session.write_transaction(add_friend, "Arthur", "Guinevere")
    session.write_transaction(add_friend, "Arthur", "Lancelot")
    session.write_transaction(add_friend, "Arthur", "Merlin")
    session.read_transaction(print_friends, "Arthur")





官方示例2：https://github.com/neo4j-examples/movies-python-bolt/blob/main/movies.py

上述程序的核心部分，抽象一下就是：

neo4j.GraphDatabase.driver(xxxx).session().write_transaction(函数(含tx.run(CQL语句)))
或

neo4j.GraphDatabase.driver(xxxx).session().begin_transaction.run(CQL语句)

附一个挺好的程序，可以直接用的：
https://blog.csdn.net/sweeper_freedoman/article/details/70231073

2、（用py2neo模块）通过操作python变量，达到操作neo4j的目的

• 官网文档：https://py2neo.org/v4/#library-reference

示例：
from py2neo import Graph, Node, Relationship
g = Graph()
tx = g.begin()
a = Node("Person", name="Alice")
tx.create(a)
b = Node("Person", name="Bob")
ab = Relationship(a, "KNOWS", b)
tx.create(ab)
tx.commit()

• 一个很好的介绍，基本操作都在里面：https://blog.csdn.net/qq_38486203/article/details/79826028

3、（用py2neo模块）执行CQL ( cypher ) 语句

• 直接看例子吧：https://github.com/neo4j-examples/movies-python-py2neo/blob/master/example.py

其中核心部分抽象就是：

py2neo.Graph(xxxx).run(CQL语句) 

返回一个二维结果