百度百科:
Neo4j是一个高性能的,NOSQL图形数据库,它将结构化数据存储在网络上而不是表中。它是一个嵌入式的、基于磁盘的、具备完全的事务特性的Java持久化引擎,但是它将结构化数据存储在网络(从数学角度叫做图)上而不是表中。Neo4j也可以被看作是一个高性能的图引擎,该引擎具有成熟数据库的所有特性。程序员工作在一个面向对象的、灵活的网络结构下而不是严格、静态的表中——但是他们可以享受到具备完全的事务特性、企业级的数据库的所有好处。
Neo4j因其嵌入式、高性能、轻量级等优势,越来越受到关注.
查询语句:
不是SQL,而是Cypher
Cypher关键点
- () 表示节点
- [] 表示关系
- {} 表示属性
- > 表示关系的方向
示例:
//查询a的一个叫duchong的朋友
match (a)-[:Friend]->b
where b.name ='duchong'
return b
一、安装Neo4j
社区版下载地址:
https://neo4j.com/artifact.php?name=neo4j-community-3.4.10-windows.zip
配置环境变量
NEO4J_HOME
Path
%NEO4J_HOME%\bin
配置完成,cmd
neo4j.bat console
启动完成 浏览器访问地址为:
localhost:7474
初始用户名和密码均为neo4j
二、springboot整合
添加依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-neo4j</artifactId>
</dependency>
properties配置
#neo4j
spring.data.neo4j.uri=http://localhost:7474
spring.data.neo4j.username=neo4j
spring.data.neo4j.password=123qwe
User节点
package com.dc.sb.web.neo4j; import org.neo4j.ogm.annotation.GraphId;
import org.neo4j.ogm.annotation.NodeEntity;
import org.neo4j.ogm.annotation.Property; /**
* 节点实体类型-别名为User
* @author DUCHONG
* @since 2018-12-17 11:32
**/
@NodeEntity(label = "User")
public class UserNode {
//图形id
@GraphId
private Long nodeId;
//属性
@Property
private String userId;
//属性
@Property
private String userName;
//属性
@Property
private int age; public Long getNodeId() {
return nodeId;
} public void setNodeId(Long nodeId) {
this.nodeId = nodeId;
} public String getUserId() {
return userId;
} public void setUserId(String userId) {
this.userId = userId;
} public String getUserName() {
return userName;
} public void setUserName(String userName) {
this.userName = userName;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
}
}
UserRelation节点
package com.dc.sb.web.neo4j; import org.neo4j.ogm.annotation.EndNode;
import org.neo4j.ogm.annotation.GraphId;
import org.neo4j.ogm.annotation.RelationshipEntity;
import org.neo4j.ogm.annotation.StartNode; /**
* 关系节点类型
* @author DUCHONG
* @since 2018-12-17 11:39
**/
@RelationshipEntity(type = "UserRelation")
public class UserRelation { @GraphId
private Long id;
//开始节点
@StartNode
private UserNode startNode;
//结束节点
@EndNode
private EndNode endNode; public Long getId() {
return id;
} public void setId(Long id) {
this.id = id;
} public UserNode getStartNode() {
return startNode;
} public void setStartNode(UserNode startNode) {
this.startNode = startNode;
} public EndNode getEndNode() {
return endNode;
} public void setEndNode(EndNode endNode) {
this.endNode = endNode;
}
}
UserRepository
package com.dc.sb.web.neo4j.dao; import com.dc.sb.web.neo4j.UserNode;
import org.springframework.data.neo4j.annotation.Query;
import org.springframework.data.neo4j.repository.GraphRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Component; import java.util.List; /**
* @author DUCHONG
* @since 2018-12-17 11:42
**/
@Component
public interface UserRepository extends GraphRepository<UserNode> { @Query("MATCH (n: User) RETURN n")
List<UserNode> getUserNodeList(); @Query("CREATE (n: User{age:{age},userName:{userName}}) RETURN n")
List<UserNode> addUserNodeList(@Param("userName") String userName, @Param("age") int age); }
UserReloationReposiroty
package com.dc.sb.web.neo4j.dao; import com.dc.sb.web.neo4j.UserRelation;
import org.springframework.data.neo4j.annotation.Query;
import org.springframework.data.neo4j.repository.GraphRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Component; import java.util.List; /**
* 用户关系DO
* @author DUCHONG
* @since 2018-12-17 13:53
**/
@Component
public interface UserRelationRepository extends GraphRepository<UserRelation> { @Query("match p= (n:User)<- [r: UserRelation]-> (n1:User) wheren.userId=(firstUserId) and n1.userId =(secondUserId) return p")
List<UserRelation> findUserRelationByEachId (@Param(" firstUserId") String firstUserId, @Param ("secondUserId") String secondUserId) ; @Query ("match(fu:User) ,(su:User) where fu. userId=[firstUserId]and su.userId=[ secondUserId, create p= (fu)- [r:UserRelation]-> (su) return p") List<UserRelation> addUserRelation (@Param(" firstUserId") String firstUserId, @Param("secondUserId") String secondUserId) ;
}
Service
package com.dc.sb.web.neo4j.service; import com.dc.sb.web.neo4j.UserNode;
import com.dc.sb.web.neo4j.dao.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service; /**
* @author DUCHONG
* @since 2018-12-17 14:02
**/
@Service
public class Neo4jUserService { @Autowired
private UserRepository userRepository; public void addUserNode(UserNode userNode){ userRepository.addUserNodeList(userNode.getUserName(),userNode.getAge());
}
}
Controller
package com.dc.sb.web.neo4j.controller; import com.dc.sb.web.neo4j.UserNode;
import com.dc.sb.web.neo4j.service.Neo4jUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; /**
* @author DUCHONG
* @since 2018-12-17 14:14
**/
@RestController
public class Neo4jController { @Autowired
private Neo4jUserService userService; @RequestMapping("/addUserNode")
public String addUserNode(){ UserNode userNode=new UserNode();
userNode.setUserName("duchong");
userNode.setAge(20); userService.addUserNode(userNode); return "add success ";
}
}
浏览器访问localhost:8080/addUserNode
查看Neo4j 数据库
完整代码已托管到GitHub ---》欢迎fork