单选或者多选的知识问题调研系统，怎么使用Neo4j的图数据库来实现

为了使用Neo4j的图数据库实现单选或多选的知识问题调研系统，你需要设计和实现以下几个步骤：

设计节点和关系
插入数据
定义查询和更新逻辑
开发前端和后端应用来与Neo4j进行交互

1. 设计节点和关系

节点类型

Question：表示一个问题，包含问题文本和类型（单选或多选）
Option：表示一个选项，包含选项文本
Response：表示一个用户的回答，用于记录用户对问题的选择

关系类型

HAS_OPTION：连接Question和Option，表示某个问题有哪些选项
LEADS_TO：连接Option和Question，表示选择某个选项后会跳转到哪个问题
ANSWERED：连接User和Response，表示用户的回答

示例图结构

(User)-[:ANSWERED]->(Response)-[:FOR]->(Question)
(Question)-[:HAS_OPTION]->(Option)
(Option)-[:LEADS_TO]->(Question)

2. 插入数据

创建问题和选项

CREATE (q1:Question {id: 1, text: '你是男方还是女方？', type: 'single'})
CREATE (q2:Question {id: 2, text: '你想咨询以下什么问题？', type: 'multiple'})
CREATE (q3:Question {id: 3, text: '你们现在有几个小孩存在抚养权问题？', type: 'single'})CREATE (o1:Option {id: 1, text: '男方'})
CREATE (o2:Option {id: 2, text: '女方'})
CREATE (o3:Option {id: 3, text: '抚养权问题'})
CREATE (o4:Option {id: 4, text: '抚养费问题'})
CREATE (o5:Option {id: 5, text: '一个'})
CREATE (o6:Option {id: 6, text: '两个'})
CREATE (o7:Option {id: 7, text: '三个及三个以上'})CREATE (q1)-[:HAS_OPTION]->(o1)
CREATE (q1)-[:HAS_OPTION]->(o2)
CREATE (q2)-[:HAS_OPTION]->(o3)
CREATE (q2)-[:HAS_OPTION]->(o4)
CREATE (q3)-[:HAS_OPTION]->(o5)
CREATE (q3)-[:HAS_OPTION]->(o6)
CREATE (q3)-[:HAS_OPTION]->(o7)CREATE (o1)-[:LEADS_TO]->(q2)
CREATE (o2)-[:LEADS_TO]->(q2)
CREATE (o3)-[:LEADS_TO]->(q3)
CREATE (o4)-[:LEADS_TO]->(q3)

3. 定义查询和更新逻辑

查询某个问题及其选项

MATCH (q:Question {id: 1})-[:HAS_OPTION]->(o:Option)
RETURN q, collect(o)

用户选择选项后，查询下一个问题

假设用户选择了"男方"（o1）

MATCH (o:Option {id: 1})-[:LEADS_TO]->(q:Question)
RETURN q

记录用户的回答

MATCH (u:User {id: 1}), (q:Question {id: 1}), (o:Option {id: 1})
CREATE (r:Response {id: 1})
CREATE (u)-[:ANSWERED]->(r)
CREATE (r)-[:FOR]->(q)
CREATE (r)-[:CHOOSE]->(o)

4. 开发前端和后端应用来与Neo4j进行交互

使用Neo4j的官方驱动程序（如Neo4j JavaScript Driver、Neo4j Python Driver）来开发与Neo4j交互的后端服务。前端应用可以使用React、Vue.js等现代前端框架来构建用户界面，通过后端API与Neo4j数据库进行通信。

示例后端API (使用Node.js和Express)

const express = require('express');
const neo4j = require('neo4j-driver');
const app = express();
const port = 3000;// 连接到Neo4j数据库
const driver = neo4j.driver('neo4j://localhost', neo4j.auth.basic('neo4j', 'password'));
const session = driver.session();app.use(express.json());// 获取问题及其选项
app.get('/question/:id', async (req, res) => {const questionId = parseInt(req.params.id);const result = await session.run('MATCH (q:Question {id: $questionId})-[:HAS_OPTION]->(o:Option) RETURN q, collect(o) AS options',{ questionId });const question = result.records[0].get('q').properties;const options = result.records[0].get('options').map(record => record.properties);res.send({ question, options });
});// 用户选择选项后获取下一个问题
app.post('/answer', async (req, res) => {const { userId, questionId, optionId } = req.body;const result = await session.run('MATCH (o:Option {id: $optionId})-[:LEADS_TO]->(q:Question) RETURN q',{ optionId });const nextQuestion = result.records[0].get('q').properties;// 记录用户的回答await session.run('MATCH (u:User {id: $userId}), (q:Question {id: $questionId}), (o:Option {id: $optionId}) ' +'CREATE (r:Response) ' +'CREATE (u)-[:ANSWERED]->(r) ' +'CREATE (r)-[:FOR]->(q) ' +'CREATE (r)-[:CHOOSE]->(o)',{ userId, questionId, optionId });res.send(nextQuestion);
});app.listen(port, () => {console.log(`App running at http://localhost:${port}`);
});

5. 开发前端应用

使用React或Vue.js等前端框架来构建用户界面，通过后端API获取问题和选项，并提交用户选择的答案。

示例前端代码 (React)

import React, { useState, useEffect } from 'react';
import axios from 'axios';const App = () => {const [question, setQuestion] = useState(null);const [options, setOptions] = useState([]);const [userId] = useState(1); // 假设用户ID为1useEffect(() => {fetchQuestion(1); // 从第一个问题开始}, []);const fetchQuestion = async (id) => {const response = await axios.get(`/question/${id}`);setQuestion(response.data.question);setOptions(response.data.options);};const handleAnswer = async (optionId) => {const response = await axios.post('/answer', {userId,questionId: question.id,optionId});fetchQuestion(response.data.id);};if (!question) return <div>Loading...</div>;return (<div><h1>{question.text}</h1><ul>{options.map(option => (<li key={option.id} onClick={() => handleAnswer(option.id)}>{option.text}</li>))}</ul></div>);
};export default App;