Neo4j GraphQL Library：OGM

https://neo4j.com/docs/graphql-manual/current/ogm/

OGM：Object Graph Mapper

使用本地Neo4j图数据库

1.启动数据库

C:\Users\bing.yao>neo4j console

2.安装graphql-ogm

C:\Users\bing.yao>npm install @neo4j/graphql-ogm

相关依赖会一并下载安装

3.创建一个空目录作为项目目录，安装Express

C:\Users\bing.yao>mkdir course_ogm
C:\Users\bing.yao>cd course_ogm
C:\Users\bing.yao\course_ogm>npm init ##采用默认值，回车几次即可
C:\Users\bing.yao\course_ogm>npm install express --save

ogm01.JPG

参考：Express，基于Node.js的Web开发框架
https://www.expressjs.com.cn/

4.在项目目录下创建index.js文件

注意：修改Neo4j图数据库连接密码

const express = require("express");
const { OGM } = require("@neo4j/graphql-ogm");
const neo4j = require("neo4j-driver");

const driver = neo4j.driver(
    "bolt://localhost:7687",
    neo4j.auth.basic("neo4j", "letmein")
);

const typeDefs = `
    type User {
        id: ID
        name: String
    }
`;

const ogm = new OGM({ typeDefs, driver });
const User = ogm.model("User");

const app = express();
app.get("/users", async (req, res) => {
    const { search, skip, limit, sort } = req.query;

    const regex = search ? `(?i).*${search}.*` : null;

    const users = await User.find({
        where: { name_REGEX: regex },
        options: {
            skip,
            limit,
            sort
        }
    });

    return res.json(users).end();
});
app.listen(4000, () => console.log("started"));

5.启动Express服务

C:\Users\bing.yao\course_ogm>node index.js

6.访问根目录（/）

http://localhost:4000/
页面显示：Hello World!，表示Express Web服务正常

7.访问users目录