# neo4jproject

**Repository Path**: zhang_renyang/neo4jproject

## Basic Information

- **Project Name**: neo4jproject
- **Description**: neo4jproject
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-07-25
- **Last Updated**: 2025-07-26

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

CREATE (a:User {name:'张三'});
CREATE (b:User {name:'李四'});
CREATE (b:User {name:'王五'});
CREATE (b:User {name:'赵六'});



MATCH (a1:User {name:'张三'}) 
MATCH (b1:User {name:'李四'}) 
CREATE (a1)-[:FRIEND]->(b1);

MATCH (a)-[:FRIEND]->(b) RETURN a,b


MATCH (a) DETACH DELETE a

MERGE (a:User {name:'张三'})-[:FRIEND]->(b:User {name:'李四'});


//创建一个图投影，包含所有的user节点和friend关系

CALL gds.graph.project(
    'myGraph',
    'User',
    'FRIEND'
)


//在myGraph图上执行pageRank算法，计算每个节点的影响力的分数
CALL gds.pageRank.stream("myGraph")
YIELD nodeId,score
RETURN gds.util.asNode(nodeId).name AS 用户,score
ORDER BY score DESC
LIMIT 5 

CALL gds.graph.drop('myGraph')

## 如何查找两个节点间的最小路径 

MATCH (a:User {name:"张三"}),(b:User {name:"王五"})
CALL apoc.algo.dijkstra(a,b,'FRIEND','weight') YIELD path,weight
RETURN  path,weight

# collect 聚合为列表
MATCH (u:User)-[:FRIEND]->(f:User)
RETURN u.name,collect(f.name) as 朋友列表

// 查询名为'张三'的User节点
MATCH (a:User {name: '张三'}) 
// 查询名为'李四'的User节点
MATCH (b:User {name: '李四'}) 
// 创建a到b之间的FRIEND关系
CREATE (a)-[:FRIEND]->(b)

// 查询名为'张三'的User节点
MATCH (a:User {name: '张三'}) 
// 查询名为'李四'的User节点
MATCH (b:User {name: '王五'}) 
// 创建a到b之间的FRIEND关系
CREATE (a)-[:FRIEND]->(b)


WITH ['张三','李四','王五'] as names
UNWIND names as name
RETURN name


# 统计每个用户的朋友数量
MATCH (u:User)-[:FRIEND]->(f:User)
RETURN u.name,size(collect(f)) AS 朋友数


CREATE (b:Book {name:'活着'});
CREATE (b:Book {name:'张三'});

// 查询朋友数大于1的用户
MATCH (u:User)-[:FRIEND]->(f:User)
WITH u, count(f) AS 朋友数
WHERE 朋友数 > 1
RETURN u.name, 朋友数

# 更新和删除

MATCH (p:User {name:'张三'})
SET p.age = 40,p.city='北京',p.email='zs@qq.com'
RETURN p


# 如果此节点有关系，则不能删除
MATCH (p:User {name:'张三'})
DELETE p

#  先删除张三的关系
MATCH (a:User {name:'张三'})-[r:FRIEND]-(b:User {name:'李四'})
DELETE r

MATCH (p:User {name:'张三'})
DETACH DELETE p


https://static.docs-hub.com/users_1753115663538.csv

LOAD CSV WITH HEADERS FROM "https://static.docs-hub.com/users_1753115663538.csv" AS row
CREATE (:User {name:row.name,age:toInteger(row.age),city:row.city})
file:///users.csv

LOAD CSV WITH HEADERS FROM "file:///users.csv" AS row
CREATE (:User {name:row.name,age:toInteger(row.age),city:row.city})


// 解析JSON并创建用户节点
CALL apoc.load.json('https://static.docs-hub.com/data_1753115997917.json') YIELD value
UNWIND value.users AS user
CREATE (:User {name: user.name, age: user.age})