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我是 mongoDb 的新手，上了一门课程，但停留在这一点上。我创建了这个 Index.js，在这里我插入一个数据并使用回调，但插入后它反映的是未定义？

--indes.js
const MongoClient = require('mongodb').MongoClient;
const assert = require('assert');

const url = 'mongodb://localhost:27017/';
const dbname = 'conFusion';

MongoClient.connect(url, (err, client) => {
    assert.equal(err, null);

    console.log('Connected correctly to server');

    const db = client.db(dbname);
    const collection = db.collection('dishes');
    collection.insertOne({ "name": "Uthappizza1", "description": "test" },
        (err, result) => {
        assert.equal(err, null);
        console.log('After Insert:\n');
        console.log(result.ops);

        collection.find({}).toArray((err, docs) => {
            assert.equal(err, null);

            console.log('Found:\n');
            console.log(docs);

            db.dropCollection('dishes', (err, result) => {
                assert.equal(err, null);

                client.close();
            });
        });
    });
});
 also attaching the package.json for more clearilty

{
  "name": "node-mongo",
  "version": "1.0.0",
  "description": "Node MongoDB Example",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "node index"
  },
  "author": "Shivam Singh",
  "license": "ISC",
  "dependencies": {
    "assert": "^2.0.0",
    "mongodb": "^4.0.1"
  }
}

我也附上截图 在此处输入图像描述

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1 回答 1

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这是因为insertOne通过回调的方法返回接口InsertOneResult的对象，根据文档，该对象只有 2 个字段：acknowledged和insertedId。由于这个原因，result.ops将永远在undefined这里，因为您确实有resultobject，但它没有 property ops。

于 2021-07-27T10:23:21.000 回答