Table of contents

1. Getting started
2. Creating your schema
3. Advanced configuration
4. Performances

You can also Start with Boilerplates

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Introduction

Graphql-Sequelize-Generator (GSG) is a set of tools that will allow you to easily generate a GraphQL API from your sequelize models.

It’s a very good fit for POCs and MVPs, while also scaling pretty well thanks to dataloader-sequelize.

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What can I do with GSG?

The tools provided by this library will allow you to:

• Query any model defined in your app through GraphQL.
• Auto-generate create/update/delete mutations.
• Define before/after hooks and all resolvers, including the mutations.
• Easily create custom mutations.
• Get an integrated interface to test your GraphQL API.
• Counts for each model can also be generated.
• Subscriptions auto-generated for mutations.
• Add custom fields/resolvers on auto-generated types.
• Easy integration with dataloader-sequelize

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Getting started

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Setting up the dependencies and the library

Add the lib and the peer dependencies of GraphQL-Sequelize-Generator:

yarn add graphql-sequelize-generator graphql sequelize graphql-sequelize @apollo/server dataloader-sequelize graphql-relay ws

⚠️ Caution: GSG requires Node v9.11.2 or greater as it is using async/await.

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Initializing the project with Sequelize-CLI and adding data to the database

If you need to initialize the project, please follow this Sequelize documentation page : Sequelize-Cli and Migrations

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Setting up your server

Create a file where you will set up your server and paste the following code. We used index.js (at the root of our example project):

// index.js
const { expressMiddleware } = require("@apollo/server/express4");
const express = require("express");
const http = require("http");
const cors = require("cors");
const json = require("body-parser");
const { createContext, EXPECTED_OPTIONS_KEY } = require("dataloader-sequelize");
const setupServer = require("./schema");
const models = require("./models"); //Assuming "models" is your import of the Sequelize models folder, initialized by Sequelize-Cli

const createServer = async (options = {}, globalPreCallback = () => null) => {
  const app = express();
  options = {
    spdy: { plain: true },
    ...options,
  };
  const httpServer = http.createServer(options, app);
  const { server } = setupServer(globalPreCallback, httpServer);
  await server.start();
  //server.applyMiddleware({ app, path: '/graphql' })
  app.use(
    "/graphql",
    cors(),
    json(),
    expressMiddleware(server, {
      context: async ({ req, connection }) => {
        const contextDataloader = createContext(models.sequelize);

        // Connection is provided when a webSocket is connected.
        if (connection) {
          // check connection for metadata
          return {
            ...connection.context,
            [EXPECTED_OPTIONS_KEY]: contextDataloader,
          };
        }
      },
    })
  );

  await new Promise((resolve) => {
    httpServer.listen(process.env.PORT || 8080, () => {
      resolve();
    });

    console.log(
      `🚀 Server ready at http://localhost:${process.env.PORT || 8080}/graphql`
    );
  });
  return httpServer;
};

const closeServer = async (server) => {
  await Promise.all([new Promise((resolve) => server.close(() => resolve()))]);
};

createServer();

In the next part, we will see how to create a schema and to insert models.

Next: Creating your schema

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Teamstarter’s other libraries

• GraphQL-Node-Jobs
  • A job scheduler, a runner and an interface to manage jobs. In one lib.
• GraphQL-Web-Hooks
  • A webhook implementation for GraphQL