[NestJS] 인프런 -따라하며 배우는 NestJS 2

Postgres & TypeORM 연동

설치할 두가지
1. PostgresSQL
2. pgAdmin (데이터베이스를 보는 툴(Tool)입니
다.)

Window 에서 PostgresSQL 설치하기
이 사이트 가서 인스톨러 다운로드
https://www.postgresql.org/download/windows/

Mac 에서 PostgresSQL 설치하기 이 사이트 가서 인스톨러 다운로드
https://postgresapp.com/downloads.html

Window & Mac 에서 pgAdmin 설치하기 이 사이트 가서 인스톨러 다운로드
https://www.pgadmin.org/download/

board-app db 생성

TypeORM 소개

TypeORM 이용

npm install pg typeorm @nestjs/typeorm --save

typeorm.config.ts

import { TypeOrmModuleOptions } from "@nestjs/typeorm";

export const typeORMConfig: TypeOrmModuleOptions = {
    type: 'postgres',
    host: 'localhost',
    port: 5432,
    username: 'postgres',
    password: 'postgres',
    database: 'board-app',
    entities: [__dirname + '/../**/*.entity.{js,ts'],
    synchronize: true
}

app.module.ts

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
import { BoardsModule } from './boards/boards.module';
import { typeORMConfig } from './boards/configs/typeorm.config';

@Module({
  imports: [TypeOrmModule.forRoot(typeORMConfig),
    BoardsModule],
  controllers: [],
  providers: [],
})
export class AppModule {}

board.entity.ts

import { BaseEntity, Column, Entity, PrimaryGeneratedColumn } from "typeorm";
import { BoardStatus } from "./boards/board-status.enum";

@Entity()
export class Board extends BaseEntity {
    @PrimaryGeneratedColumn()
    id: number;

    @Column()
    title: string;

    @Column()
    description: string;

    @Column()
    status: BoardStatus;
}

board.repository.ts

import { EntityRepository, Repository } from "typeorm";
import { Board } from "./board.entity";

@EntityRepository(Board)
export class BoardRepository extends Repository<Board> {
    
}

board.module.ts

import { Module } from '@nestjs/common';
import { TypeOrmModule } from '@nestjs/typeorm';
import { BoardRepository } from 'src/board.repository';
import { BoardsController } from './boards.controller';
import { BoardsService } from './boards.service';

@Module({
  imports: [
    TypeOrmModule.forFeature([BoardRepository])
  ],
	...
})
export class BoardsModule {}

데이터베이스를 이용한 CRUD 구현

ID를 이용해서 특정 게시물 가져오기

게시물 생성하기

게시물 삭제하기

board.repository.ts

import { EntityRepository, Repository } from "typeorm";
import { BoardStatus } from "./board-status.enum";
import { Board } from "./board.entity";
import { CreateBoardDto } from "./dto/create-board.dto";

@EntityRepository(Board)
export class BoardRepository extends Repository<Board> {
    
    async createBoard(createBoardDto: CreateBoardDto): Promise<Board> {
        const {title, description} =  createBoardDto;
        
        const board = this.create({
            title,
            description,
            status: BoardStatus.PUBLIC
        })

        await this.save(board);
        return board;
    }
}

board.service.ts

import { Injectable, NotFoundException } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { NotFoundError } from 'rxjs';
import { Board } from 'src/boards/board.entity';
import { BoardStatus } from './board-status.enum';
import { BoardRepository } from './board.repository';
import { CreateBoardDto } from './dto/create-board.dto';

@Injectable()
export class BoardsService {
    constructor(
        @InjectRepository(BoardRepository)
        private boardRepository: BoardRepository
    ){}

    async getAllBoards(): Promise <Board[]> {
        return this.boardRepository.find();
    }

    createBoard(createBoardDto: CreateBoardDto): Promise<Board> {
        return this.boardRepository.createBoard(createBoardDto);
    }

    async getBoardById(id: number): Promise<Board> {
        const found = await this.boardRepository.findOne(id);

        if (!found) {
            throw new NotFoundException(`Can't find the board with id ${id}`);
        }

        return found;
    }

    async deleteBoard(id: number): Promise<void> {
        const result = await this.boardRepository.delete(id);
        
        if (result.affected === 0) {
            throw new NotFoundException(`Can't find Board with id ${id}`);
        }
    }
    
    async updateBoardStatus(id: number, status: BoardStatus): Promise<Board> {
        const board = await this.getBoardById(id);

        board.status = status;
        await this.boardRepository.save(board);

        return board;
    }
 }

board.controller.ts

import { Body, Controller, Delete, Get, Param, ParseIntPipe, Patch, Post, UsePipes, ValidationPipe } from '@nestjs/common';

import { BoardStatus } from './board-status.enum';
import { Board } from './board.entity';
import { BoardsService } from './boards.service';
import { CreateBoardDto } from './dto/create-board.dto';
import { BoardStatusValidationPipe } from './pipes/board-status-validation.pipes';

@Controller('boards')
export class BoardsController {
    constructor(private boardsService: BoardsService) {}

    @Get('/')
    getAllBoard(): Promise<Board[]> {
        return this.boardsService.getAllBoards();
    }

    @Post()
    @UsePipes(ValidationPipe)
    createBoard(@Body() CreateBoardDto: CreateBoardDto): Promise<Board> {
        return this.boardsService.createBoard(CreateBoardDto);
    }

    @Get('/:id')
    getBoardById(@Param('id') id: number): Promise<Board> {
        return this.boardsService.getBoardById(id);
    }

    @Delete('/:id')
    deleteBoard(@Param('id', ParseIntPipe) id): Promise<void> {
        return this.boardsService.deleteBoard(id);
    }

    @Patch('/:id/status')
    updateBoardStatus(
        @Param('id', ParseIntPipe) id: number,
        @Body('status', BoardStatusValidationPipe) status: BoardStatus
    ) {
        return this.boardsService.updateBoardStatus(id, status);
    }
}

ParseIntPipe는 숫자만 들어오도록 만들어진 파이프다.

모듈 구조가 중요하다. 첨에 실습했을 때 Board의 Metadata를 못찾는다는 에러가 나왔는데, typeorm.config.ts에 엔티티의 위치가 상대경로로 들어가있어서 그런듯하다.