Part 4: Building a REST API with NestJS and Prisma: Handling Relational Data

prisma/migrations/20230414070358_add_user_model/migration.sql

@@ -0,0 +1,18 @@
+-- AlterTable
+ALTER TABLE `article` ADD COLUMN `authorId` INTEGER NULL;
+
+-- CreateTable
+CREATE TABLE `User` (
+    `id` INTEGER NOT NULL AUTO_INCREMENT,
+    `name` VARCHAR(191) NULL,
+    `email` VARCHAR(191) NOT NULL,
+    `password` VARCHAR(191) NOT NULL,
+    `createdAt` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3),
+    `updatedAt` DATETIME(3) NOT NULL,
+
+    UNIQUE INDEX `User_email_key`(`email`),
+    PRIMARY KEY (`id`)
+) DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
+
+-- AddForeignKey
+ALTER TABLE `Article` ADD CONSTRAINT `Article_authorId_fkey` FOREIGN KEY (`authorId`) REFERENCES `User`(`id`) ON DELETE SET NULL ON UPDATE CASCADE;

prisma/schema.prisma

@@ -18,4 +18,16 @@ model Article {
   published   Boolean  @default(false)
   createdAt   DateTime @default(now())
   updatedAt   DateTime @updatedAt
+  author      User?    @relation(fields: [authorId], references: [id])
+  authorId    Int?
+}
+
+model User {
+  id        Int       @id @default(autoincrement())
+  name      String?
+  email     String    @unique
+  password  String
+  createdAt DateTime  @default(now())
+  updatedAt DateTime  @updatedAt
+  articles  Article[]
 }

prisma/seed.ts

@@ -6,31 +6,71 @@ import { PrismaClient } from "@prisma/client";
 const prisma = new PrismaClient();
 
 async function main() {
+    // create two dummy users
+    const user1 = await prisma.user.upsert({
+        where: { email: 'sabin@adams.com' },
+        update: {},
+        create: {
+            email: 'sabin@adams.com',
+            name: 'Sabin Adams',
+            password: 'password-sabin',
+        },
+    });
+
+
+    const user2 = await prisma.user.upsert({
+        where: { email: 'alex@ruheni.com' },
+        update: {},
+        create: {
+            email: 'alex@ruheni.com',
+            name: 'Alex Ruheni',
+            password: 'password-alex',
+        },
+    });
+
     // create two dummy articles
     const post1 = await prisma.article.upsert({
         where: { title: 'Prisma Adds Support for MongoDB' },
-        update: {},
+        update: {
+            authorId: user1.id,
+        },
         create: {
             title: 'Prisma Adds Support for MongoDB',
             body: 'Support for MongoDB has been one of the most requested features since the initial release of...',
             description: "We are excited to share that today's Prisma ORM release adds stable support for MongoDB!",
             published: false,
+            authorId: user1.id,
         }
     })
 
     const post2 = await prisma.article.upsert({
         where: { title: "What's new in Prisma? (Q1/22)" },
-        update: {},
+        update: {
+            authorId: user2.id,
+        },
         create: {
             title: "What's new in Prisma? (Q1/22)",
             body: 'Our engineers have been working hard, issuing new releases with many improvements...',
             description:
                 'Learn about everything in the Prisma ecosystem and community from January to March 2022.',
             published: true,
+            authorId: user2.id,
+        },
+    });
+
+    const post3 = await prisma.article.upsert({
+        where: { title: 'Prisma Client Just Became a Lot More Flexible' },
+        update: {},
+        create: {
+            title: 'Prisma Client Just Became a Lot More Flexible',
+            body: 'Prisma Client extensions provide a powerful new way to add functionality to Prisma in a type-safe manner...',
+            description:
+                'This article will explore various ways you can use Prisma Client extensions to add custom functionality to Prisma Client..',
+            published: true,
         },
     });
 
-    console.log({ post1, post2 });
+    console.log({ user1, user2, post1, post2, post3 });
 }
 
 // execute the main function

src/app.module.ts

@@ -3,9 +3,10 @@ import { AppController } from './app.controller';
 import { AppService } from './app.service';
 import { PrismaModule } from './prisma/prisma.module';
 import { ArticlesModule } from './articles/articles.module';
+import { UsersModule } from './users/users.module';
 
 @Module({
-  imports: [PrismaModule, ArticlesModule],
+  imports: [PrismaModule, ArticlesModule, UsersModule],
   controllers: [AppController],
   providers: [AppService],
 })

src/articles/articles.controller.ts

@@ -12,26 +12,28 @@ export class ArticlesController {
 
   @Post()
   @ApiCreatedResponse({ type: ArticleEntity })
-  create(@Body() createArticleDto: CreateArticleDto) {
-    return this.articlesService.create(createArticleDto);
+  async create(@Body() createArticleDto: CreateArticleDto) {
+    return new ArticleEntity(await this.articlesService.create(createArticleDto));
   }
 
   @Get('drafts')
   @ApiOkResponse({ type: ArticleEntity, isArray: true })
-  findDrafts() {
-    return this.articlesService.findDrafts();
+  async findDrafts() {
+    const drafts = await this.articlesService.findDrafts()
+    return drafts.map((draft) => new ArticleEntity(draft))
   }
 
   @Get()
   @ApiOkResponse({ type: ArticleEntity, isArray: true })
-  findAll() {
-    return this.articlesService.findAll();
+  async findAll() {
+    const articles = await this.articlesService.findAll()
+    return articles.map((article) => new ArticleEntity(article))
   }
 
   @Get(':id')
   @ApiOkResponse({ type: ArticleEntity })
   async findOne(@Param('id', ParseIntPipe) id: number) {
-    const article = await this.articlesService.findOne(id)
+    const article = new ArticleEntity(await this.articlesService.findOne(id))
     if (!article) {
       throw new NotFoundException(`Article with ${id} does not exist.`)
     }
@@ -40,13 +42,13 @@ export class ArticlesController {
 
   @Patch(':id')
   @ApiOkResponse({ type: ArticleEntity })
-  update(@Param('id', ParseIntPipe) id: number, @Body() updateArticleDto: UpdateArticleDto) {
-    return this.articlesService.update(id, updateArticleDto);
+  async update(@Param('id', ParseIntPipe) id: number, @Body() updateArticleDto: UpdateArticleDto) {
+    return new ArticleEntity(await this.articlesService.update(id, updateArticleDto));
   }
 
   @Delete(':id')
   @ApiOkResponse({ type: ArticleEntity })
-  remove(@Param('id', ParseIntPipe) id: number) {
-    return this.articlesService.remove(id);
+  async remove(@Param('id', ParseIntPipe) id: number) {
+    return new ArticleEntity(await this.articlesService.remove(id));
   }
 }

src/articles/articles.service.ts

@@ -20,7 +20,11 @@ export class ArticlesService {
   }
 
   findOne(id: number) {
-    return this.prisma.article.findUnique({ where: { id } })
+    return this.prisma.article.findUnique({
+      where: { id }, include: {
+        author: true
+      }
+    })
   }
 
   update(id: number, updateArticleDto: UpdateArticleDto) {

src/articles/entities/article.entity.ts

@@ -1,5 +1,6 @@
 import { Article } from '@prisma/client'
 import { ApiProperty } from '@nestjs/swagger'
+import { UserEntity } from 'src/users/entities/user.entity'
 
 export class ArticleEntity implements Article {
     @ApiProperty()
@@ -22,4 +23,18 @@ export class ArticleEntity implements Article {
 
     @ApiProperty()
     updatedAt: Date
+
+    @ApiProperty({ required: false, nullable: true })
+    authorId: number | null;
+
+    @ApiProperty({ required: false, type: UserEntity })
+    author?: UserEntity
+
+    constructor({ author, ...data }: Partial<ArticleEntity>) {
+        Object.assign(this, data)
+
+        if (author) {
+            this.author = new UserEntity(author)
+        }
+    }
 }

src/main.ts

@@ -1,13 +1,14 @@
-import { HttpAdapterHost, NestFactory } from '@nestjs/core';
+import { HttpAdapterHost, NestFactory, Reflector } from '@nestjs/core';
 import { AppModule } from './app.module';
 import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
-import { ValidationPipe } from '@nestjs/common'
+import { ClassSerializerInterceptor, ValidationPipe } from '@nestjs/common'
 import { PrismaClientExceptionFilter } from './prisma-client-exception/prisma-client-exception.filter';
 
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
 
   app.useGlobalPipes(new ValidationPipe({ whitelist: true }))
+  app.useGlobalInterceptors(new ClassSerializerInterceptor(app.get(Reflector)))
 
   const config = new DocumentBuilder()
     .setTitle('Median')

src/users/dto/create-user.dto.ts

@@ -0,0 +1,20 @@
+import { ApiProperty } from "@nestjs/swagger";
+import { IsNotEmpty, IsString, MinLength } from "class-validator";
+
+export class CreateUserDto {
+    @IsString()
+    @IsNotEmpty()
+    @ApiProperty()
+    name: string
+
+    @IsString()
+    @IsNotEmpty()
+    @ApiProperty()
+    email: string
+
+    @IsString()
+    @IsNotEmpty()
+    @MinLength(6)
+    @ApiProperty()
+    password: string
+}

src/users/dto/update-user.dto.ts

@@ -0,0 +1,4 @@
+import { PartialType } from '@nestjs/swagger';
+import { CreateUserDto } from './create-user.dto';
+
+export class UpdateUserDto extends PartialType(CreateUserDto) {}

src/users/entities/user.entity.ts

@@ -0,0 +1,27 @@
+import { ApiProperty } from '@nestjs/swagger'
+import { User } from '@prisma/client'
+import { Exclude } from 'class-transformer'
+
+export class UserEntity implements User {
+    constructor(partial: Partial<UserEntity>) {
+        Object.assign(this, partial)
+    }
+
+    @ApiProperty()
+    id: number
+
+    @ApiProperty()
+    createdAt: Date
+
+    @ApiProperty()
+    updatedAt: Date
+
+    @ApiProperty()
+    name: string
+
+    @ApiProperty()
+    email: string
+
+    @Exclude()
+    password: string
+}

src/users/users.controller.spec.ts

@@ -0,0 +1,20 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { UsersController } from './users.controller';
+import { UsersService } from './users.service';
+
+describe('UsersController', () => {
+  let controller: UsersController;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      controllers: [UsersController],
+      providers: [UsersService],
+    }).compile();
+
+    controller = module.get<UsersController>(UsersController);
+  });
+
+  it('should be defined', () => {
+    expect(controller).toBeDefined();
+  });
+});

src/users/users.controller.ts

@@ -0,0 +1,43 @@
+import { Controller, Get, Post, Body, Patch, Param, Delete, ParseIntPipe } from '@nestjs/common';
+import { UsersService } from './users.service';
+import { CreateUserDto } from './dto/create-user.dto';
+import { UpdateUserDto } from './dto/update-user.dto';
+import { ApiCreatedResponse, ApiOkResponse, ApiTags } from '@nestjs/swagger';
+import { UserEntity } from './entities/user.entity';
+
+@Controller('users')
+@ApiTags('users')
+export class UsersController {
+  constructor(private readonly usersService: UsersService) { }
+
+  @Post()
+  @ApiCreatedResponse({ type: UserEntity })
+  async create(@Body() createUserDto: CreateUserDto) {
+    return new UserEntity(await this.usersService.create(createUserDto));
+  }
+
+  @Get()
+  @ApiOkResponse({ type: UserEntity, isArray: true })
+  async findAll() {
+    const users = await this.usersService.findAll()
+    return users.map((user) => new UserEntity(user))
+  }
+
+  @Get(':id')
+  @ApiOkResponse({ type: UserEntity })
+  async findOne(@Param('id', ParseIntPipe) id: number) {
+    return new UserEntity(await this.usersService.findOne(id));
+  }
+
+  @Patch(':id')
+  @ApiOkResponse({ type: UserEntity })
+  async update(@Param('id', ParseIntPipe) id: number, @Body() updateUserDto: UpdateUserDto) {
+    return new UserEntity(await this.usersService.update(id, updateUserDto));
+  }
+
+  @Delete(':id')
+  @ApiOkResponse({ type: UserEntity })
+  async remove(@Param('id', ParseIntPipe) id: number) {
+    return new UserEntity(await this.usersService.remove(id));
+  }
+}

src/users/users.module.ts

@@ -0,0 +1,11 @@
+import { Module } from '@nestjs/common';
+import { UsersService } from './users.service';
+import { UsersController } from './users.controller';
+import { PrismaModule } from 'src/prisma/prisma.module';
+
+@Module({
+  controllers: [UsersController],
+  providers: [UsersService],
+  imports: [PrismaModule]
+})
+export class UsersModule { }

src/users/users.service.spec.ts

@@ -0,0 +1,18 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { UsersService } from './users.service';
+
+describe('UsersService', () => {
+  let service: UsersService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [UsersService],
+    }).compile();
+
+    service = module.get<UsersService>(UsersService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+});

src/users/users.service.ts

@@ -0,0 +1,29 @@
+import { Injectable } from '@nestjs/common';
+import { CreateUserDto } from './dto/create-user.dto';
+import { UpdateUserDto } from './dto/update-user.dto';
+import { PrismaService } from 'src/prisma/prisma.service';
+
+@Injectable()
+export class UsersService {
+  constructor(private prisma: PrismaService) { }
+
+  create(createUserDto: CreateUserDto) {
+    return this.prisma.user.create({ data: createUserDto })
+  }
+
+  findAll() {
+    return this.prisma.user.findMany()
+  }
+
+  findOne(id: number) {
+    return this.prisma.user.findUnique({ where: { id } })
+  }
+
+  update(id: number, updateUserDto: UpdateUserDto) {
+    return this.prisma.user.update({ where: { id }, data: updateUserDto })
+  }
+
+  remove(id: number) {
+    return this.prisma.user.delete({ where: { id } })
+  }
+}