NodeJS Sequelize 从查询中返回数据

use*_*157 3 node.js promise express sequelize.js

对 Javascript 和 Node.js 来说是全新的。我正在尝试开始使用 Sequelize 作为 ORM 并做了一个简单的查询

var employeeList = Employee.findAll().then(function(result){
    console.log(result.length);
    console.log(result[0].employeeName);
    //how do I return this to a variable with which I can do further processing
    return result;
 });

//do something with employeeList
employeeList[0].employeeName //cannot read property of undefined 
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虽然控制台日志打印出正确的名字,但employeeList 本身不包含任何数据。我尝试打印employeeList,它显示了承诺

Promise {
  _bitField: 0,
  _fulfillmentHandler0: undefined,
  _rejectionHandler0: undefined,
  _promise0: undefined,
  _receiver0: undefined }
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我确实浏览了 promise 的概念,但无法得到一个关于如何将 promise 的结果返回到函数外部变量的东方示例。我认为返回结果可以解决问题。我在这里错过了什么吗?我可以理解我可以在 promise 函数中处理结果。如果场景是进行两次数据库调用,然后处理两次调用的结果以返回合并结果,那么如何在不将结果传递给变量的情况下完成此操作。

小智 5

因此,根据您关于使用独立查询的评论的帖子,我想向您展示如何正确使用它们:

//Each request in it's own function to respect the single responsability principle 
function getAllEmployees() {
  return Employee
    .findAll()
    .then(function(employees){
      //do some parsing/editing
      //this then is not required if you don't want to change anything
      return employees;
     });
}

function doAnotherJob() {
  return YourModel
    .findAll()
    .then(function(response) => {
      //do some parsing/editing
      //this then is not required if you don't want to change anything
      return response;
    });
}

function do2IndependentCalls() {
  return Promise.all([
    getAllEmployees(),
    doAnotherJob()
  ]).then(([employees, secondRequest]) => {
    //do the functionality you need
  })
}
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