Question

我使用mongodb和mongoose的promises时遇到了问题。这是我的沙箱代码：

'use strict';

const mongoose = require('mongoose');

// Use JS native Promises to handle mongo promises
mongoose.Promise = Promise;

mongoose.connect("mongodb://localhost:27017/sandbox");

let db = mongoose.connection;

db.on('error', (err) => {
    console.error(err);
});

db.once("open", () => {
    console.log('Database connection successful');
    // All database communication goes here

    const AnimalSchema = new mongoose.Schema({
        type: { type: String, default: "goldfish" },
        size: { type: String, default: "small" },
        color: { type: String, default: "golden" },
        mass: { type: Number, default: 0.007 },
        name: { type: String, default: "Angela" }
    });

    let Animal = mongoose.model('Animal', AnimalSchema);
    let elephant = new Animal({
        type: 'elephant',
        size: 'big',
        color: 'gray',
        mass: 6000,
        name: 'Lawrence'
    });

    let animal = new Animal({}); // Goldfish

    let whale = new Animal({
        type: 'whale',
        size: 'big',
        mass: 190500,
        name: 'Fig'
    });

    Animal
        .remove({})
        .then(elephant.save())
        .then(whale.save())
        .then(animal.save())
        // Find all big animals
        .then(Animal.find({ size: 'big' }).exec())

        // ERROR HERE
        .then((err, animals) => {
            animals.forEach(animal => console.log(`${animal.name} is ${animal.color} ${animal.type}`));
            // console.log(err, animals);
        })
        .then(() => {
            console.log('Saved!');
            db.close().then(() => console.log('db connection closed'));
        })
        .catch((err) => {
            console.error("Save Failed", err);
        });
});

问题是，当我尝试在终端中执行此代码时，我收到错误：保存失败TypeError：无法读取属性＆＃39; forEach＆＃39;未定义的在Animal.remove.then.then.then.then.then（C：_projects \ express_api \ mongoose_sandbox.js：54：11）

我的伐木活动有什么问题？

MongoDB承诺链错误

0 个答案: