如何为 MySQL 模型制作 GraphQL 模式？

Posted 2023-03-08

【中文标题】如何为 MySQL 模型制作 GraphQL 模式？

【英文标题】：How to make GraphQL schema for MySQL models?

【发布时间】：2018-01-25 01:01:45

【问题描述】：

我在mysql中有下表。

用户

CREATE TABLE users(
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(255) UNIQUE NOT NULL,
    email VARCHAR(255) UNIQUE NOT NULL,
    password VARCHAR(100) NOT NULL,
    created_at TIMESTAMP DEFAULT NOW()
);

和帖子

CREATE TABLE posts(
    id INTEGER AUTO_INCREMENT PRIMARY KEY,
    created_by INTEGER NOT NULL,
    created_at TIMESTAMP DEFAULT NOW(),
    post_title VARCHAR(100) NOT NULL UNIQUE,
    post_body VARCHAR(255) NOT NULL,
    slug VARCHAR(100) NOT NULL UNIQUE,
    FOREIGN KEY (created_by) REFERENCES users(id)
);

我正在使用 nodejs 和 mysql npm 包。如何为模型制作 graphQL 架构？

我搜索了很多，但没有找到任何解决方案。大多数人为此目的使用sequelize。是不是比mysql包好？

【问题讨论】：

好吧，这似乎是一个维护得当的解决方案：github.com/mickhansen/graphql-sequelize

已经看到了。我是否需要从我正在使用的 mysql 转移到续集。你能告诉我使用 sequelize 代替 mysql npm 包是否明智？

【参考方案1】：

是的，你可以使用 sequelize orm 将 graphql 连接到 Mysql 数据库

参考：- http://docs.sequelizejs.com/manual/installation/getting-started

给出了示例架构和解析器

Schema.js

const typeDefinitions = `



type Author 

  authorId: Int
  firstName: String
  lastName: String
  posts: [Post]



type Post 

  postId: Int
  title: String 
  text: String
  views: Int
  author: Author



input postInput
  title: String 
  text: String
  views: Int



type Query 

  author(firstName: String, lastName: String): [Author]
  posts(postId: Int, title: String, text: String, views: Int): [Post]





type Mutation 

createAuthor(firstName: String, lastName: String, posts:[postInput]): Author

updateAuthor(authorId: Int, firstName: String, lastName: String, posts:[postInput]): String




schema 
  query: Query
  mutation:Mutation

`;

export default [typeDefinitions];

connectors.js

import rp from 'request-promise';
var Sequelize = require('sequelize');
var db = new Sequelize('test', 'postgres', 'postgres', 
  host: '192.168.1.168',
  dialect: 'postgres',

  pool: 
    max: 5,
    min: 0,
    idle: 10000
  

);


const AuthorModel = db.define('author', 
  authorId:  type: Sequelize.INTEGER, primaryKey: true, autoIncrement: true, field: "author_id" ,
  firstName:  type: Sequelize.STRING, field: "first_name" ,
  lastName:  type: Sequelize.STRING, field: "last_name" ,
,
        freezeTableName: false,
        timestamps: false,
        underscored: false,
        tableName: "author"
    );


const PostModel = db.define('post', 
    postId:  type: Sequelize.INTEGER, primaryKey: true, autoIncrement: true, field: "post_id" ,
  text:  type: Sequelize.STRING ,
  title:   type: Sequelize.STRING ,
  views:  type: Sequelize.INTEGER ,
,
        freezeTableName: false,
        timestamps: false,
        underscored: false,
        tableName: "post"
    );


AuthorModel.hasMany(PostModel, 
    foreignKey: 'author_id'
);
PostModel.belongsTo(AuthorModel, 
    foreignKey: 'author_id'
);

const Author = db.models.author;
const Post = db.models.post;

export  Author, Post ;

解析器.js

import  Author  from './connectors';
import  Post  from './connectors';


const resolvers = 

  Query: 
    author(_, args) 
      return Author.findAll( where: args );
    ,
    posts(_, args) 
      return Post.findAll( where: args );
    
  ,

  Mutation: 

    createAuthor(_, args) 
      console.log(args)
      return Author.create(args, 
        include: [
          model: Post,
        ]
      );
    ,

    updateAuthor(_, args) 

      var updateProfile =  title: "name here" ;
      console.log(args.authorId)
      var filter = 
        where: 
          authorId: args.authorId
        ,
        include: [
           model: Post 
        ]
      ;
      Author.findOne(filter).then(function (product) 
        Author.update(args,  where:  authorId: args.authorId  ).then(function (result) 
          product.posts[0].updateAttributes(args.posts[0]).then(function (result) 
            //return result;
          )
        );
      )
      return "updated";
    ,

  ,


  Author: 
    posts(author) 
      return author.getPosts();
    ,
  ,
  Post: 
    author(post) 
      return post.getAuthor();
    ,
  ,
;

export default resolvers;

【参考方案2】：

您可以尝试一个名为 SwitchQL (github.com/SwitchQL/SwitchQL) 的新开源工具。我已经在这个项目上工作了一段时间。

您将连接字符串传递给它，它会返回在现有数据库之上运行 graphql 服务器所需的一切。它还返回符合 Apollo 的客户端突变和查询。

我们目前只支持 Postgres，但如果您想帮助我们支持 MySQL，请告诉我！