typescript - 如何将“then”回调函数的结果返回到 loopback 4 控制器

Question

我正在尝试在我的 loopback4 控制器内的 TypeORM 实体上执行“查找”功能。

问题是，根据 TypeORM 文档，我已经在附加到“createConnection”函数的“then”回调函数中执行了查询。因此，“findOne”调用的结果超出了控制器方法的范围

//this is the controller method signature
async findById(@param.path.number('id') id: number): Promise<Pratica> {

    createConnection({
      type: 'oracle',
      host: '10.64.2.226',
      port: 1521,
      sid: 'NPRA02S',
      username: 'sua03e',
      password: 'iniziale',
      entities: [
        Pratica
      ],
      logging: true
    }).then(async connection => {
      let praticaRepository = connection.getRepository(Pratica);

      // I have to return this as a result parameter in the controller
      let pratica = await praticaRepository.findOne({ protocolloaci: id });

    }).catch(error => console.log(error));

  }

我也尝试过以下方法，但我会知道如何在没有 async/await 的情况下进行管理

//this is the controller method signature
async findById(@param.path.number('id') id: number): Promise<Pratica> {

    let connection = await createConnection({
      type: 'oracle',
      host: '10.64.2.226',
      port: 1521,
      sid: 'NPRA02S',
      username: 'sua03e',
      password: 'iniziale',
      entities: [
        Pratica
      ],
      logging: true
    })

    let praticaRepository = connection.getRepository(Pratica);

    return await praticaRepository.findOne({ protocolloaci: id }) || new Pratica;

  }

先感谢您

标签： typescripttypeormloopback4

Answer 1

试试下面的代码

async findById(@param.path.number('id') id: number): Promise<Pratica> {

        return new Promise( (resolve)=>{

            createConnection({
              type: 'oracle',
              host: '10.64.2.226',
              port: 1521,
              sid: 'NPRA02S',
              username: 'sua03e',
              password: 'iniziale',
              entities: [
                Pratica
              ],
              logging: true
            }).then(async connection => {
              let praticaRepository = connection.getRepository(Pratica);

              // I have to return this as a result parameter in the controller
              const pratica = await praticaRepository.findOne({ protocolloaci: id });
              resolve(pratica); // return using resolve
            }).catch(error => console.log(error));
        });
}