Introduction

There is an example project for you to play with.

Setup

Clone the example

# The example folder is used during development, hence it is inside the main repo
git clone https://github.com/charlie0077/graphql-server-crud

Launch database

cd graphql-server-crud/example/database
docker-compose up # this will launch the database

The user name, password, database are all "test"; port number is 6666.

You can also use your own database instead of this docker. In that case, remember to update the database configuration here.

Launch grapqhql api server

cd graphql-server-crud/example
npm install
npm run seed # this will seed the data
npm start

WARNING

COMPATIBILITY NOTE: This example code requires Node.js >= 12.

You should be able to access the graphql playground on http://localhost:4000/

Try query in the playground

Run the following graphql query.

query {
  queryPost(
    where: { id: { gt: 1 } }
    offset: 0
    limit: 5
    orderBy: { column: "id", order: "asc" }
  ) {
    id
    title
    author {
      email
      company {
        domain
      }
    }
  }
}

You should be able to see result similar to the following.

{
  "data": {
    "queryPost": [
      {
        "id": 2,
        "title": "new post 2222",
        "author": {
          "email": "wicisu@sefnevpur.si",
          "company": {
            "domain": "wofizrak.ke"
          }
        }
      },
      {
        "id": 3,
        "title": "Ipnek bacepos di pen subnuran paheog duhnab cihonzi.",
        "author": {
          "email": "novme@pocogov.sb",
          "company": {
            "domain": "vafdose.gb"
          }
        }
      },
      {
        "id": 4,
        "title": "Odovo gezde catug leogdu fino jag tikih jailho.",
        "author": {
          "email": "fop@dek.bs",
          "company": {
            "domain": "vazili.ws"
          }
        }
      },
      {
        "id": 5,
        "title": "Ado dogva ricab tupbaobe ir me rosgekpag eroberogi.",
        "author": null
      },
      {
        "id": 6,
        "title": "Cuckoboz dijjujat zovucini ikle nog ube ahuvohaf ujane.",
        "author": {
          "email": "zoc@cowibgeh.cz",
          "company": null
        }
      }
    ]
  }
}

Let's check the queries excuted

In the backend, only 2 queries is executed. N+1 problem is not an issue in the library.

> nodemon example/index.js

[nodemon] 2.0.2
[nodemon] to restart at any time, enter `rs`
[nodemon] watching dir(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node example/index.js`
🚀  Server ready at http://localhost:4000/ 
----------  SEARCH QUERY (Post) ---------
 select "posts"."id" as "id", "posts"."title" as "title", "posts"."id" as "id" from "posts" where "posts"."id" > 1 order by "posts"."id" asc limit 5

----------  SEARCH QUERY (Post) ---------
 select "posts"."id" as "crud_base___id", "authors"."email" as "authors___email", "authors"."id" as "authors___id", "companies"."domain" as "companies___domain", "companies"."id" as "companies___id" from "posts" left join "authors" on "posts"."author_id" = "authors"."id" left join "companies" on "authors"."company_id" = "companies"."id" where "posts"."id" in (2, 3, 4, 5, 6)