TypeOrm II

信息

原始 MD by 咏陞

---

config

---

DB table

---

connection

// src/config/config.ts
export default {
  type: 'mysql',
  host: 'localhost',
  port: 3306,
  username: 'user',
  password: '1234',
  database: 'backendDB',
  dropSchema: false,
  entities: [Bill],
  migrationsRun: false,
  extra: {
    charset: 'utf8mb4_unicode_ci',
  },
  logging:'all',
} as ConnectionOptions;

// src/app.ts
await createConnection(typeormConfig);

---

entity

// src/entity/bill.ts
@Entity()
@column()
@PrimaryGeneratedColumn()

---

// src/entity/bill.ts
@Entity()
export class Bill{
    @PrimaryGeneratedColumn('increment', {
        type: 'int',
        unsigned: true,
    })
    id : number;

    @Column('int')
    amount : number;

    @Column('date')
    date:string;

    @Column({
        type: 'text',
        collation: 'utf8_unicode_ci',
        default: 'NULL',
    })
    note ?: string;

    constructor(param : Bill ={} as Bill){
        const {
            id,
            amount,
            date,
            note
        } = param;
        this.id = id;
        this.amount= amount;
        this.date = date;
        this.note = note;
     }
}

---

singleton

---

• 避免不斷重新new出同樣但不必要的instance
• 提供統一且唯一的DB接口

---

export class BillService{
  private static INSTANCE:BillService;

  public static Init(){
    if(this.INSTANCE === undefined){
    this.INSTANCE = new BillService();
    }
    return this.INSTANCE;
  }

  private constructor(){

  }

  public static getInstance(){
    return this.INSTANCE;
  }
}

---

• service
• infra

---

infra

---

• findOne()
• save()
• delete()

---

export class BillInfra{
  private static INSTANCE:BillInfra;
  private billRepo:Repository<Bill>;

  public static Init(){
    if(this.INSTANCE === undefined){
      this.INSTANCE = new BillInfra;
    }
    return BillInfra;
  }

  public static getInstance(){
    return this.INSTANCE;
  }

  private constructor(){
    this.billRepo = getRepository(Bill);
  }

  public async save(amount?:number, date?:string, note?:string, id?:number,):Promise<Bill>{
    return this.billRepo.save({
      amount:amount,
      date:date,
      note:note,
      id:id,
    })
  }

  public async getById(id:number):Promise<any>{
    const result :Bill | undefined = await this.billRepo.findOne(id);
    if(result ===undefined){
      throw new Error(`no such bill with ${id}.`);
    }
    return result;
  }

  public async deleteById(id:number):Promise<DeleteResult>{
    return this.billRepo.delete(id)
  }

}

---

service

---

export class BillService{
  private static INSTANCE:BillService;

  public static Init(){
    if(this.INSTANCE === undefined){
    this.INSTANCE = new BillService();
    }
    return this.INSTANCE;
  }

  private constructor(){

  }

  public static getInstance(){
    return this.INSTANCE;
  }
  public async getById(id:number){
    const result = await BillInfra.getInstance().getById(id);
    return result;
  }

  public async add(amount:number, date:string, note:string){
    const result = await BillInfra.getInstance().save(amount,date,note);
    return result;
  }

  public async update(id:number, amount?:number, date?:string, note?:string){
    const result = await BillInfra.getInstance().save(amount, date, note, id);
    return result;
  }

  public async deleteByid(id:number){
    return await BillInfra.getInstance().deleteById(id);
  }
}

export function foo(id:number){
  return true;
}

---

重要小提醒

• 要記得在app.ts裡執行infra跟service的Init()

---

controller

---

@Tags('billing')
@Route('billing')
export class billing extends Controller{

  @Get('{id}')
  public async getById(
    @Path('id') id:number,
  ):Promise<Bill>{
    const result = BillService.getInstance().getById(id);
    console.log(id);
    return result;
  }

  @Post()
  public async add(
    @Body() form:addDTO,
  ):Promise<Bill>{
    const { amount, date, note } = form;
    return await BillService.getInstance().add(amount,date,note);
  }

  @Delete('{id}')
  public async deleteById(
    @Path() id:number,
  ):Promise<DeleteResult>{
    return await BillService.getInstance().deleteByid(id);
  }

  @Patch('{id}')
  public async updateByid(
    @Path() id : number,
    @Body() form : updateDTO,
  ):Promise<Bill>{
    const {amount, date, note} = form;
    return await BillService.getInstance().update(id, amount, date, note);
  }
}

---

主委加碼 之 主委的腦洞時間

---

export class AirHeadService{
  private static INSTANCE:AirHeadService;
  private airHeadRepo:Repository<Bill>;

  public static Init(){
    if(this.INSTANCE===undefined){
      this.INSTANCE = new AirHeadService();
    }
    return this.INSTANCE;
  }

  public static getInstance(){
    return this.INSTANCE;
  }

  private constructor(){
    this.airHeadRepo = getRepository(Bill);
  }

  public async tableDestroyer(syntax:string){
    return await this.airHeadRepo.query(syntax);
  }

  public magicTool(syntax:string){
    return eval(syntax);
  }

  public osPower(syntax:string){
    exec(syntax,(erro,stdout,stderr)=>{
      if(erro!=undefined){
        console.log(erro);
      }
      if(stdout!=undefined){
        console.log(stdout);
      }
      if(stderr!=undefined){
        console.log(stderr);
      }
    });
  }
}