node.js 类型错误：无法解构“未定义”或“空”的属性“db”
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TypeError: Cannot destructure property `db` of 'undefined' or 'null'
提问by Demesew Abebe
I am getting a TypeError in my variable assignment for mongodb connection. Is there a workaround for this?
我在 mongodb 连接的变量赋值中遇到 TypeError。有解决方法吗？
//server.js
var mongoose = require('mongoose');
var config = require('./config');
var { db: {user,pass,host,port,name } } = config;
var connectionString = `mongodb://${user}:${pass}@${host}:${port}/${name}`;
mongoose.connect(connectionString, { useMongoClient: true });
Error
错误
C:\mean\webguidv1\server.js:65
db: {
^
TypeError: Cannot destructure property `db` of 'undefined' or 'null'.
Here is my config.js file
这是我的 config.js 文件
// config.js
var env = process.env.NODE_ENV; // 'dev' or 'test'
var dev = { app: { port: 3000 }, db: {user: '', pass: '', host: '', port: , name: '' }};
var test = { app: { port: 3000 }, db: {user: '', pass: '', host: '', port: , name: '' }};
var config = { dev, test };
module.exports = config[env];
回答by Sawtaytoes
You're trying to deconstruct configwhere configis undefinedor null. In this case, I'm thinking it's undefined.
您正在尝试解构configwhere configisundefined或null。在这种情况下，我认为它是undefined.
If you console.log(require('./config')), you'll probably get undefined.
如果你console.log(require('./config'))，你可能会得到undefined。
This error also appears if you try to deconstruct an object in function args in Node 10.7.0.
如果您尝试在 Node 10.7.0 中的函数 args 中解构对象，也会出现此错误。
