the guide to setup NestJS, TypeORM, MySQL,GraphQL for Backend Development

 here is a step to follow in order to setup a backend development with TypeORM, MySQL

1. install NestJS CLI

    yarn add -g @nestjs/cli

2. create a nestjs app

    nest new my-project

3. install @nestjs/typerom typreorm mysql2 (mysql 2 is much typescript friendly than mysql)

    yarn add @nestjs/typeorm typeorm mysql2 

4. create a TypeORM config JSON file to store typeorm configuation.

    touch ormconfig.json

5. paste the following into the ormconfig.json file

    {

   "type": "mysql",
   "host": "localhost",
   "port": 3306,
   "username": "test",
   "password": "test",
   "database": "test",
   "synchronize": true,
   "logging": false,
   "entities": [
      "src/entity/**/*.ts"
   ],
   "migrations": [
      "src/migration/**/*.ts"
   ],
   "subscribers": [
      "src/subscriber/**/*.ts"
   ]
}

6. add @nestjs/config package to the project so that we can use ConfigureModule module to access the configuration file.

    yarn add @nestjs/config 

7.  add a database module to the project

    touch database.module.ts

8. add the following code the database.module.ts to setup the database connection.

import { Module } from '@nestjs/common';

import { TypeOrmModule } from '@nestjs/typeorm';

import { Connection } from 'typeorm';

@Module({

  imports: [TypeOrmModule.forRoot()],

  exports: [TypeOrmModule],

})

export class DatabaseModule {

  constructor(connection: Connection) {

    if (connection.isConnected) {

      console.log('DB connected Successfully');

    }

  }

}

9. add DatabaseModule to the app.module.ts file    

import { Module } from '@nestjs/common';

import { ConfigModule } from '@nestjs/config';

import { AppController } from './app.controller';

import { AppService } from './app.service';

import { DatabaseModule } from './database/database.module';

@Module({

  imports: [ConfigModule.forRoot(), DatabaseModule],

  controllers: [AppController],

  providers: [AppService],

})

export class AppModule {}

10. execute yarn start to launch the project and you will see the DB connection had been established.

DB connected Successfully

[Nest] 16320  - 2021-07-10, 9:02:02 p.m.     LOG [InstanceLoader] TypeOrmCoreModule dependencies initialized +26ms

[Nest] 16320  - 2021-07-10, 9:02:02 p.m.     LOG [InstanceLoader] DatabaseModule dependencies initialized +1ms

[Nest] 16320  - 2021-07-10, 9:02:02 p.m.     LOG [RoutesResolver] AppController {/}: +5ms

[Nest] 16320  - 2021-07-10, 9:02:02 p.m.     LOG [RouterExplorer] Mapped {/, GET} route +3ms

[Nest] 16320  - 2021-07-10, 9:02:02 p.m.     LOG [NestApplication] Nest application successfully started +2ms

11. add Graphql to the project

yarn add @nestjs/graphql graphql-tools graphql apollo-server-express

you might encounter  missing package errors here, you can manually add them as following

yarn add ts-morph @apollo/gateway

12. add GraphQLModule to the app.module.ts to initialze GraphQL Module

import { Module } from '@nestjs/common';

import { ConfigModule } from '@nestjs/config';

import { GraphQLModule } from '@nestjs/graphql';

import { AppController } from './app.controller';

import { AppService } from './app.service';

import { ComponentModule } from './components/comonents.module';

import { DatabaseModule } from './database/database.module';

@Module({

  imports: [

    ConfigModule.forRoot(),

    DatabaseModule,

    GraphQLModule.forRoot({

      playground: process.env.NODE_DEV === 'dev',

      debug: process.env.NODE_DEV === 'dev',

      autoSchemaFile: true,

    }),

    ComponentModule,

  ],

  controllers: [AppController],

  providers: [AppService],

})

export class AppModule {}

Further reading

NestJS Dccument

TypeORM - Amazing ORM for TypeScript and JavaScript ES7