go mod init github.com/masudur-rahman/hackernews

go get -d github.com/99designs/gqlgen
go run github.com/99designs/gqlgen init

go run github.com/99designs/gqlgen generate

 printf '// +build tools\npackage tools\nimport (_ "github.com/99designs/gqlgen"\n _ "github.com/99designs/gqlgen/graphql/introspection")' | gofmt > tools.go\n\ngo mod tidy
 rm -rf vendor
 go run github.com/99designs/gqlgen generate
 go mod tidy && go mod vendor

Note: If you are getting validation failed: packages.Load error. It may occur, because gqlgen uses todo project as starter template. To get rid of this error, edit graph/schema.resolvers.go file and delete functions CreateTodo and Todos. Now run the command again.

docker run -p 3306:3306 --name mysql -e MYSQL_ROOT_PASSWORD=mysql -e MYSQL_DATABASE=hackernews -d mysql:latest

It will start a MySQL Server with a root:mysql user and a database named hackernews

docker rm mysql -f

docker exec -it mysql bash

> mysql -u root -p
>> mysql # password

# Basic pre commands
> show databases;
> use hackernews;
> show tables;
> describe Users;

We need to create migrations for our app so every time our app runs it creates tables it needs to work properly, we are going to use golang-migrate package. Create a folder structure for our database files in the project root directory:

go-graphql-hackernews
--internal
----pkg
------db
--------migrations
----------mysql

go get -u github.com/go-sql-driver/mysql
go build -tags 'mysql' -ldflags="-X main.Version=1.0.0" -o $GOPATH/bin/migrate github.com/golang-migrate/migrate/v4/cmd/migrate/
cd internal/pkg/db/migrations/
migrate create -ext sql -dir mysql -seq create_users_table
migrate create -ext sql -dir mysql -seq create_links_table

migrate command will create two files for each migration ending with .up and .down; up is responsible for applying migration and down is responsible for reversing it. Open 000001_create_users_table.up.sql and add table for our users:

CREATE TABLE IF NOT EXISTS Users(
    ID INT NOT NULL UNIQUE AUTO_INCREMENT,
    Username VARCHAR (127) NOT NULL UNIQUE,
    Password VARCHAR (127) NOT NULL,
    PRIMARY KEY (ID)
)

in 000002_create_links_table.up.sql:

CREATE TABLE IF NOT EXISTS Links(
    ID INT NOT NULL UNIQUE AUTO_INCREMENT,
    Title VARCHAR (255) ,
    Address VARCHAR (255) ,
    UserID INT ,
    FOREIGN KEY (UserID) REFERENCES Users(ID) ,
    PRIMARY KEY (ID)
)

We need one table for saving links and one table for saving users.

migrate -database mysql://root:dbpass@/hackernews -path internal/pkg/db/migrations/mysql up

NB: The migration is added to the starting of the GraphQL Server. So, we don't need to run it manually.

go run server/server.go

You will find a GraphQL Playground here. You can test the defined queries and mutations here. Here's some example queries and mutations.

mutation createUser {
  createUser(input: {username: "masud", password: "password"})
}

mutation login {
  login(input: {username: "masud", password: "password"})
}

mutation createLink {
  createLink(input: {title: "something", address: "somewhere"}) {
    title
    address
    id
    user {
      name
    }
  }
}

• With a Additional Request Header

  {
      "Authorization": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE2Njg3ODgyODAsInVzZXJuYW1lIjoibWFzdWQifQ.3G0dggzOSXimbszXsD1yrTGlXgANhGyWrbf2S9vPHRU"
  }

query links {
  links {
    title
    address,
    id
    user {
      name
    }
  }
}