Sequelize update 改变预初始化变量答案

【问题标题】：Sequelize update change the pre-initialized variableSequelize update 改变预初始化变量
【发布时间】：2017-02-28 12:09:48
【问题描述】：

我正在尝试在更新之前将续集实例保存到变量中。但是在更新之后，旧变量也会更新到新的sequelize实例中，这使得变量'oldRequest'前后的.description不同。

var oldRequest = request; // HUGE BUG HERE, OLD REQUEST IS ALSO MODIFIED AS REQUEST IS MODIFIED
        console.log("before " + oldRequest.description);
        attributes.lastUpdater = req.user.get('firstName') + " " + req.user.get('lastName');
        request.update(attributes).then(function(updatedRequest) {
            console.log("after " + oldRequest.description);
            send_update_email(oldRequest ,updatedRequest, req.user.get('email')).then(function() {

【问题讨论】：

标签： node.js sqlite sequelize.js

【解决方案1】：

问题是oldRequest 实际上只是引用同一个对象request。请参阅此问题以获得深入的解释：Javascript pointer/reference craziness. Can someone explain this?

如果您需要保存 description，请尝试使用克隆：（有关详细信息，请参阅此答案：Cloning an Object in Node.js）

var extend = require('util')._extend;
var oldRequest = extend({}, request);
...

【讨论】：