Sequelize - 自定义创建方法答案

【问题标题】：Sequelize - Custom Create MethodSequelize - 自定义创建方法
【发布时间】：2017-02-13 03:58:54
【问题描述】：

是否可以在Sequelize 中创建自定义create 方法。我想要它，以便我可以传入一个 URL 以从中下载缩略图照片，然后使用该数据调用一个方法来下载照片，将其上传到 S3，并将该 S3 URL 保存为 thumbnailPhotoURL。

这是我尝试执行的语法示例：

var Sequelize = require('sequelize');
var sequelize = new Sequelize('database', 'username', 'password');

var User = sequelize.define('user', {
  username: Sequelize.STRING,
  birthday: Sequelize.DATE,
  thumbnailPhotoURL: Sequelize.STRING
});

sequelize.sync().then(function() {
  return User.create({
    username: 'janedoe',
    birthday: new Date(1980, 6, 20),
    // this will be used to download and upload the thumbnailPhoto to S3
    urlToDownloadThumbnailPhotoFrom: 'http://example.com/test.png'
  });
}).then(function(jane) {
  console.log(jane.get({
    plain: true
  }));
});

注意我是如何使用urlToDownloadThumbnailPhotoFrom 参数而不是thumbnailPhotoURL 参数调用User.create

【问题讨论】：

标签： node.js express sequelize.js

【解决方案1】：

可以在创建前使用钩子，无需定义自定义创建函数

var Sequelize = require('sequelize');
var sequelize = new Sequelize('database', 'username', 'password');

var User = sequelize.define('user', {
  username: Sequelize.STRING,
  birthday: Sequelize.DATE,
  thumbnailPhotoURL: Sequelize.STRING
});


User.beforeCreate(function(model, options, cb) { 
   var urlToDownloadThumbnailPhotoFrom = model.urlToDownloadThumbnailPhotoFrom;


//.....Here you write the logic to get s3 url using urlToDownloadThumbnailPhotoFrom and then assign it to model and call the call back it will automatically get saved

  model.thumbnailPhotoURL = thumbnailPhotoURL;
  cb();
});

【讨论】：