前置知识
1.Neo4j :属性
节点和关系都可以设置自己的属性。 属性是由Key-Value键值对组成，键名是字符串。属性值是要么是原始值，要么是原始值类型的一个数组。比如+String+，+int+和i+int[]+都是合法的。
注意
null不是一个合法的属性值。 Nulls能代替模仿一个不存在的Key。
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属性值类型
TypeDescriptionValue rangebooleantrue/false byte8-bit integer-128 to 127, inclusiveshort16-bit integer-32768 to 32767, inclusiveint32-bit integer-2147483648 to 2147483647, inclusivelong64-bit integer-9223372036854775808 to 9223372036854775807, inclusivefloat32-bit IEEE 754 floating-point number double64-bit IEEE 754 floating-point number char16-bit unsigned integers representing Unicode charactersu0000 to uffff (0 to 65535)Stringsequence of Unicode characters 如果要了解float/double类型的更多细节，请参考：Java Language Specification。
2.Cypher语法
本人Cypher语法 同样小白 仅分享（有不正确的地方请包涵）
neo4j 中文网
节点操作
创建节点
创建一个标签为zhan的节点 （标签：将数据进行分类，方便管理）
create(n:zhan);// 这里的n就是随便起的一个变量名，代指当前实体或者关系。创建一个标签为zhan 且带有属性值的节点
create(n:zhan{id:1,name:'小明',age:20});查询节点
按照标签查询
match (n:zhan) return n; 按照id进行查询
match (n:zhan) where id(n) = 38023 return n;多属性条件查询
match (n:zhan) where n.name = '小明'and n.age = 20 and n.id = 1 return n;添加多标签
match (n:zhan) where id(n) = 38023 set n:zhan1 return n;match (n:zhan) where id(n) = 38023 set n:zhan2 return n;移除标签
match (n:zhan) where id(n) = 38023 remove n:zhan2 return n;match (n:zhan) where id(n) = 38023 remove n:zhan1 return n;修改属性
match (n:zhan) where n.name='小明' set n.name = '小红' return n;match (n:zhan) where n.name='小明' set n.name = '小红' set n.age = '200'return n;删除实体
match (n:zhan) where n.name = '小王' delete n;相信 已发现 规律 * —— *
关系操作
新建关系和实体
1. 无实体create (n:zhan{name:'小张'})-[r:test] -> (m:zhan{name:'小李'})create (n:zhan{name:'小黄'})-[r:test{name:'夫妻'}] -> (m:zhan{name:'小八'})2.有实体match (n:zhan),(m:zhan) where n.name = '小李' and m.name = '小八' create (n)-[r:test{name:'儿子'}]->(m) ;修改属性
match p = (n)-[r:test]->(m) where r.name='朋友' set r.name='闺蜜' return p;关系添加属性
match p = (n)-[r:test]->(m) where r.name='闺蜜' set r.color='红色' return p;删除关系
match (n)-[r:relation]->(m) where r.name = '闺蜜' delete r;修改标签
【注意】neo4j是不支持修改关系标签
修改标签的操作是重新创建一个关系删除原关系
MATCH (n)-[r:test]->(m) where r.name='闺蜜'#搜出来想要修改的关系CREATE (n)-[r2:relation]->(m)# 新建关系SET r2 = r # copy原属性DELETE r # 删除高级搜索 …
3.Spring boot ,Maven 基本知识
Neo4j + Java api
1.Maven
【注意】：Spring boot 版本 2.2 以上
<dependency><groupId>org.neo4j</groupId><artifactId>neo4j-ogm-http-driver</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-neo4j</artifactId></dependency>2.application.yml
neo4j:uri: bolt://******:***username: neo4jpassword: ''3.Node 类
4.关系类
@RelationshipEntity //表示关系类型@Data //get set@AllArgsConstructor//会生成一个包含所有变量的构造方法，默认生成的方法是 public 的@NoArgsConstructor // 生成一个无参数的构造方法public class KnowledgePointsRelation {@Id@GeneratedValueprivate Long id;private Date createTime;private String name;/** *起始节点的实体 */@StartNodeprivate KnowledgePointsNose KnowledgePointsFrom;/** * 终止节点的实体 */@EndNodeprivate KnowledgePointsNoseKnowledgePointsTo;public KnowledgePointsRelation(KnowledgePointsNose KnowledgePointsFrom,KnowledgePointsNose KnowledgePointsTo,String name){this.KnowledgePointsFrom=KnowledgePointsFrom;this.KnowledgePointsTo=KnowledgePointsTo;this.name=name;}}Repository层
public interface KnowledgePointsNoseRepository extends Neo4jRepository<KnowledgePointsNose,Long> {}public interface KnowledgePointsRelationRepository extends Neo4jRepository<KnowledgePointsRelation,Long> {}同样：
neo4j 结合现有方法
//// Source code recreated from a .class file by IntelliJ IDEA// (powered by FernFlower decompiler)//package org.springframework.data.repository;import java.util.Optional;@NoRepositoryBeanpublic interface CrudRepository<T, ID> extends Repository<T, ID> {<S extends T> S save(S var1);<S extends T> Iterable<S> saveAll(Iterable<S> var1);Optional<T> findById(ID var1);boolean existsById(ID var1);Iterable<T> findAll();Iterable<T> findAllById(Iterable<ID> var1);long count();void deleteById(ID var1);void delete(T var1);void deleteAll(Iterable<" />extends T> var1);void deleteAll();}Test(测试新增)
CustomerNode customerNode=new CustomerNode();customerNode.setName(name);customerNode.setAge(age);customerRepository.save(customerNode);CustomerNode customerNodeTo=customerRepository.findByName(nameTo);if(customerNodeTo !=null){CustomerRelation customerRelation=new CustomerRelation(customerNode,customerNodeTo,remark);customerRelationRepository.save(customerRelation);}