知识图谱

知识图谱（Knowledge Graph），在图书情报界称为知识域可视化或知识领域映射地图，是显示知识发展进程与结构关系的一系列各种不同的图形，用 可视化技术描述知识资源及其载体，挖掘、分析、 构建、绘制和显示知识及它们之间的相互联系。 知识图谱是通过将应用数学、 图形学、信息可视化技术、 信息科学等学科的理论与方法与计量学引文分析、共现分析等方法结合，并利用可视化的图谱形象地展示学科的核心结构、发展历史、 前沿领域以及整体知识架构达到多学科融合目的的现代理论。它能为学科研究提供切实的、有价值的参考。

Neo4j

安装

切换jdk版本(neo4j-community-4.4.4需要jdk11):

rmdir "D:\Software\Java\default"
mklink /J "D:\Software\Java\default" "C:\Program Files\Java\jdk-11.0.13"

解压缩安装并设置环境变量:

mklink /J "D:\Software\Neo4j\default" "D:\Software\Neo4j\neo4j-community-4.4.4"
setx NEO4J_HOME "D:\Software\Neo4j\default" /m

# 控制台启动
<NEO4J_HOME>\bin\neo4j console
# 安装为服务
<NEO4J_HOME>\bin\neo4j install-service

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样例

页面访问：http://localhost:7474/browser/

  • 初始账号：neo4j/neo4j
    创建图库(样例)：
  • :play movie graph
  • :play northwind graph
    image.png

使用

  1. 删除所有的图: MATCH (n) DETACH DELETE n
  2. 创建一个人物节点: CREATE (n:Person {name:'John'}) RETURN n
    image.png
  3. 创建更多人物节点：
CREATE (n:Person {name:'Sally'}) RETURN n;
CREATE (n:Person {name:'Steve'}) RETURN n;
CREATE (n:Person {name:'Mike'}) RETURN n;
CREATE (n:Person {name:'Liz'}) RETURN n;
CREATE (n:Person {name:'Shawn'}) RETURN n;
  1. 查看整个图库：match(n) return n;
    image.png
  2. 创建地区
CREATE (n:Location {city:'Miami', state:'FL'});
CREATE (n:Location {city:'Boston', state:'MA'});
CREATE (n:Location {city:'Lynn', state:'MA'});
CREATE (n:Location {city:'Portland', state:'ME'});
CREATE (n:Location {city:'San Francisco', state:'CA'});
  1. 创建关联关系(Liz和Mike之间建立了FRIENDS关系)
    MATCH (a:Person {name:'Liz'}),(b:Person {name:'Mike'}) MERGE (a)-[:FRIENDS]->(b);
  2. 在关系中添加属性(Shawn和Sally在2001年后建立了FRIENDS关系)
    MATCH (a:Person {name:'Shawn'}), (b:Person {name:'Sally'}) MERGE (a)-[:FRIENDS {since:2001}]->(b);
  3. 添加更多的FRIENDS关系
MATCH (a:Person {name:'Shawn'}), (b:Person {name:'John'}) MERGE (a)-[:FRIENDS {since:2012}]->(b);
MATCH (a:Person {name:'Mike'}), (b:Person {name:'Shawn'}) MERGE (a)-[:FRIENDS {since:2006}]->(b);
MATCH (a:Person {name:'Sally'}), (b:Person {name:'Steve'}) MERGE (a)-[:FRIENDS {since:2006}]->(b);
  1. 建立MARRIED关系
MATCH (a:Person {name:'Liz'}), (b:Person {name:'John'}) MERGE (a)-[:MARRIED {since:1998}]->(b);

image.png
10. 建立人物和地点的关系

MATCH (a:Person {name:'John'}), (b:Location {city:'Boston'}) MERGE (a)-[:BORN_IN {year:1978}]->(b);
MATCH (a:Person {name:'Liz'}), (b:Location {city:'Boston'}) MERGE (a)-[:BORN_IN {year:1981}]->(b);
MATCH (a:Person {name:'Mike'}), (b:Location {city:'San Francisco'}) MERGE (a)-[:BORN_IN {year:1960}]->(b);
MATCH (a:Person {name:'Shawn'}), (b:Location {city:'Miami'}) MERGE (a)-[:BORN_IN {year:1960}]->(b);
MATCH (a:Person {name:'Steve'}), (b:Location {city:'Lynn'}) MERGE (a)-[:BORN_IN {year:1970}]->(b);

image.png
11. 查询下所有在Boston出生的人物
MATCH (a:Person)-[:BORN_IN]->(b:Location {city:'Boston'}) RETURN a,b
image.png
12. 查询所有对外有关系的节点(所有的地区都没有对外关系，只有人物建立了对外关系)
MATCH (a)-->() RETURN a
image.png
13. 查询所有有关系的节点: MATCH (a)--() RETURN a
14. 查询所有对外有关系的节点，以及关系类型: MATCH (a)-[r]->() RETURN a.name, type(r)
image.png
15. 查询有婚姻关系的节点: MATCH (n)-[:MARRIED]-() RETURN n
16. 创建节点的时候就建好关系
CREATE (a:Person {name:'Todd'})-[r:FRIENDS]->(b:Person {name:'Carlos'})
17. 查找Mike的朋友的朋友
MATCH (a:Person {name:'Mike'})-[r1:FRIENDS]-()-[r2:FRIENDS]-(friend_of_a_friend) RETURN friend_of_a_friend.name AS fofName
18. 增加/修改节点的属性

MATCH (a:Person {name:'Liz'}) SET a.age=34;
MATCH (a:Person {name:'Shawn'}) SET a.age=32;
MATCH (a:Person {name:'John'}) SET a.age=44;
MATCH (a:Person {name:'Mike'}) SET a.age=25;
  1. 删除节点属性
MATCH (a:Person {name:'Mike'}) SET a.test='test';
MATCH (a:Person {name:'Mike'}) REMOVE a.test;
  1. 删除节点
    MATCH (a:Location {city:'Portland'}) DELETE a;
  2. 删除有关系的节点
    MATCH (a:Person {name:'Todd'})-[rel]-(b:Person) DELETE a,b,rel;