Add Department module for relationship

src/app.module.ts

@@ -14,6 +14,7 @@ import { AllExceptionsFilter } from './logger/any-exception.filter';
 import loggerMiddleware from './logger/logger.middleware';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { StaffsModule } from './staffs/staffs.module';
+import { DepartmentModule } from './department/department.module';
 
 @Module({
   imports: [
@@ -30,11 +31,13 @@ import { StaffsModule } from './staffs/staffs.module';
       // entities: ['dist/modules/**/*.mysql.entity{.ts,.js}'],
       autoLoadEntities: true,
       // IMPORTANT: disable sync
-      // synchronize: false,
-      synchronize: true,
+      synchronize: false,
+      // synchronize: true,
+      logging: true,
     }),
     UsersModule,
     StaffsModule,
+    DepartmentModule,
   ],
   controllers: [AppController],
   providers: [

src/department/README.md

@@ -0,0 +1,10 @@
+# Department Module
+
+- This module demonstrates using:
+    - CRUD
+    - TypeORM: MySQL
+    - TypeORM Repository
+    - No QueryBuilder
+    - TypeOrmModule.forFeature & TypeOrmModule.forRoot{ autoLoadEntities: true }
+- The Entities
+    - DB and Web-API entities are shared

src/department/department.controller.ts

@@ -0,0 +1,78 @@
+import {
+  Controller,
+  Get,
+  Post,
+  Body,
+  Patch,
+  Param,
+  Delete,
+  NotFoundException,
+  HttpCode,
+  BadRequestException,
+} from '@nestjs/common';
+import { ApiResponse } from '@nestjs/swagger';
+import { DepartmentService } from './department.service';
+import { Department } from './entities/department.entity';
+import { DepartmentCreateDto } from './dto/department-create.dto';
+import { DepartmentUpdateDto } from './dto/department-update.dto';
+import { EntityNotFoundError } from 'typeorm';
+
+@Controller('department')
+export class DepartmentController {
+  constructor(private readonly departmentService: DepartmentService) {}
+
+  private handleEntityNotFoundError(id: number, e: Error) {
+    if (e instanceof EntityNotFoundError) {
+      throw new NotFoundException(`Not found: id=${id}`);
+    } else {
+      throw e;
+    }
+  }
+
+  @Get()
+  @ApiResponse({ type: [Department] })
+  findAll(): Promise<Department[]> {
+    return this.departmentService.findAll();
+  }
+
+  @Get(':id')
+  @ApiResponse({ type: Department })
+  async findOne(@Param('id') id: number): Promise<Department | null> {
+    // NOTE: the + operator returns the numeric representation of the object.
+    return this.departmentService.findOne(+id).catch((err) => {
+      this.handleEntityNotFoundError(id, err);
+      return null;
+    });
+  }
+
+  @Post()
+  @ApiResponse({ type: [Department] })
+  create(@Body() departmentCreateDto: DepartmentCreateDto) {
+    return this.departmentService.create(departmentCreateDto);
+  }
+
+  @Patch(':id')
+  // Status 204 because no content will be returned
+  @HttpCode(204)
+  async update(
+    @Param('id') id: number,
+    @Body() departmentUpdateDto: DepartmentUpdateDto,
+  ): Promise<void> {
+    if (Object.keys(departmentUpdateDto).length === 0) {
+      throw new BadRequestException('Request body is empty');
+    }
+    await this.departmentService
+      .update(+id, departmentUpdateDto)
+      .catch((err) => {
+        this.handleEntityNotFoundError(id, err);
+      });
+  }
+
+  @Delete(':id')
+  @HttpCode(204)
+  async remove(@Param('id') id: number): Promise<void> {
+    await this.departmentService.remove(+id).catch((err) => {
+      this.handleEntityNotFoundError(id, err);
+    });
+  }
+}

src/department/department.module.ts

@@ -0,0 +1,15 @@
+import { Logger, Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { DepartmentService } from './department.service';
+import { DepartmentController } from './department.controller';
+import { Department } from './entities/department.entity';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([Department])],
+  controllers: [DepartmentController],
+  providers: [Logger, DepartmentService],
+  // If you want to use the repository outside of the module
+  // which imports TypeOrmModule.forFeature, you'll need to re-export the providers generated by it.
+  // exports: [TypeOrmModule],
+})
+export class DepartmentModule {}

src/department/department.service.ts

@@ -0,0 +1,55 @@
+import { Injectable, Logger, NotFoundException } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { EntityNotFoundError, Repository } from 'typeorm';
+import { Department } from './entities/department.entity';
+import { DepartmentCreateDto } from './dto/department-create.dto';
+import { DepartmentUpdateDto } from './dto/department-update.dto';
+
+@Injectable()
+export class DepartmentService {
+  constructor(
+    private readonly logger: Logger,
+    @InjectRepository(Department)
+    private departmentRepository: Repository<Department>,
+  ) {}
+
+  create(departmentCreateDto: DepartmentCreateDto): Promise<Department> {
+    // Use Repository.create() will copy the values to destination object.
+    const department = this.departmentRepository.create(departmentCreateDto);
+    return this.departmentRepository.save(department);
+  }
+
+  findAll(): Promise<Department[]> {
+    return this.departmentRepository.find();
+  }
+
+  findOne(id: number): Promise<Department> {
+    return this.departmentRepository.findOneOrFail({ where: { id } });
+  }
+
+  async update(
+    id: number,
+    departmentUpdateDto: DepartmentUpdateDto,
+  ): Promise<void> {
+    await this.isExist(id);
+    await this.departmentRepository.update({ id }, departmentUpdateDto);
+  }
+
+  async remove(id: number): Promise<void> {
+    await this.isExist(id);
+    await this.departmentRepository.delete(id);
+  }
+
+  // Helper function: Check if the entity exist.
+  // If entity does not exsit, return the Promise.reject()
+  private async isExist(id: number): Promise<void> {
+    const cnt = await this.departmentRepository.countBy({ id });
+    if (cnt > 0) {
+      return;
+    } else {
+      return Promise.reject(
+        new EntityNotFoundError(Department, { where: { id } }),
+      );
+    }
+  }
+}

src/department/dto/department-create.dto.ts

@@ -0,0 +1,16 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { IsNotEmpty, IsString } from 'class-validator';
+export class DepartmentCreateDto {
+  // NOTE: Since the id is auto-inc, so no id for the creation
+  // id: number;
+
+  @ApiProperty({
+    type: String,
+    name: 'name',
+    description: 'Department name',
+    required: true,
+  })
+  @IsString()
+  @IsNotEmpty()
+  name: string;
+}

src/department/dto/department-update.dto.ts

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

src/department/entities/department.entity.ts

@@ -0,0 +1,30 @@
+import { ApiProperty } from '@nestjs/swagger';
+import { Staff } from 'src/staffs/entities/staff.entity';
+import { Column, Entity, OneToMany, PrimaryGeneratedColumn } from 'typeorm';
+
+// @Entity('departments')
+@Entity()
+export class Department {
+  @ApiProperty({
+    type: Number,
+    name: 'id',
+    description: 'id of department, auto-incremented',
+    required: true,
+  })
+  @PrimaryGeneratedColumn('increment')
+  id: number;
+
+  @ApiProperty({
+    type: String,
+    name: 'name',
+    description: 'Department name',
+    required: true,
+  })
+  @Column({
+    type: 'varchar',
+  })
+  name: string;
+
+  // @OneToMany((type) => Staff, (staff) => staff.departmentId)
+  // staffs: Staff[];
+}

src/staffs/entities/staff.entity.ts

@@ -1,11 +1,19 @@
 import { ApiProperty } from '@nestjs/swagger';
-import { Column, Entity, PrimaryGeneratedColumn } from 'typeorm';
+import { Department } from 'src/department/entities/department.entity';
+import {
+  Column,
+  Entity,
+  JoinColumn,
+  JoinTable,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+} from 'typeorm';
 
 // @Entity('staffs')
 @Entity()
 export class Staff {
   @ApiProperty({
-    type: 'number',
+    type: Number,
     name: 'id',
     description: 'id of staff, auto-incremented',
     required: true,
@@ -53,5 +61,7 @@ export class Staff {
   })
   departmentId: number;
 
-  // TODO: JOIN TABLE CASE
+  @ManyToOne(() => Department)
+  @JoinColumn({ name: 'department_id' })
+  department: Department;
 }

src/staffs/staffs.service.ts

@@ -20,7 +20,21 @@ export class StaffsService {
   }
 
   findAll(): Promise<Staff[]> {
-    return this.staffsRepository.find();
+    return this.staffsRepository.find({
+      relations: {
+        department: true,
+      },
+      select: {
+        id: true,
+        name: true,
+
+        departmentId: false,
+        department: {
+          id: false,
+          name: true,
+        },
+      },
+    });
   }
 
   findOne(id: number): Promise<Staff> {

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

@@ -10,7 +10,7 @@ import {
 export class CreateUserDto {
   // NOTE: Since the id is autoinc, so no id for user creation
   // @ApiProperty({
-  //   type: 'number',
+  //   type: Number,
   //   name: 'id',
   //   description: 'id of user',
   //   required: false,

src/users/entities/user.entity.ts

@@ -11,7 +11,7 @@ import { UpdateUserDto } from '../dto/update-user.dto';
 // export class User implements IUser {
 export class User {
   @ApiProperty({
-    type: 'number',
+    type: Number,
     name: 'id',
     description: 'id of user',
     required: false,
@@ -19,7 +19,7 @@ export class User {
   id: number;
 
   @ApiProperty({
-    type: 'string',
+    type: String,
     name: 'name',
     description: 'name of user',
     required: false,