我想在我的数据库中实现一个简单的更新，但我在控制台中得到了这个 { ok: 0, n: 0, nModified: 0 }？

Question

# I can't update keep getting { ok: 0, n: 0, nModified: 0 } ！ # ... const mongoose = require('mongoose'); mongoose.connect('mongodb://localhost:27017/mongo-exercises', {useNewUrlParser: true, useUnifiedTopology: true }) ... .then(() => console.log('连接到 MongoDB...')) .catch(() => console.error('Could not connect to MongoDB...', err));

...

    const courseSchema = new mongoose.Schema({
        tags: [String],
        date: {type: Date, default: Date.now},
        name: String,
        isPublished: Boolean,
        author: String,
        Price: Number
    ...
    });
    ...


 const Course = mongoose.model('Course', courseSchema);

 async function updateCourse(id){
    const result = await Course.updateOne({_id: id}, {
        $set: {
            author: 'Momo',
            isPublished: true
        }
    });
...

    console.log(result);    //{ n: 0, nModified: 0, ok: 1 }

}

...

 updateCourse('5a68ff090c553064a218a547');

块引用

Answer 1

你可以试试这个。

const result = await Course.updateOne({_id: id}, {
        $set: {
            author: 'Momo',
            isPublished: true
        },
      {new:true}
    }).lean();

Answer 2

我明白了。我确实从 json 文件将数据导入到我的数据库中，并且 id 没有 ObjectId，并且不适用于较新版本的 mongoose。

所以 id 是这样的："_id":"5a68fdc3615eda645bc6bdec"

这是 mongoose 5.9.18 的正确方式："_id": ObjectId("5a68fdc3615eda645bc6bdec")

Answer 3

const mongoose = require('mongoose');
async function connectDatabase() {
    try {
        await mongoose.connect('mongodb://localhost/newdb21', {
            useNewUrlParser: true,
            useUnifiedTopology: true,
            useFindAndModify: false,
            useCreateIndex: true
          }).then(console.log('successfully connected to MongoDb'));
    } catch(err) {
        console.log('Could not connect to the database');
    }
}
connectDatabase();
    
// define a schema to store data
const courseSchema = mongoose.Schema({
    name: { type: String, required: true },
    price: Number,
    isPublised:{ type:Boolean, default:false},
    tags: [String],
    date: { type: Date, default: Date.now },
    author: String
});

// create a mode for the course
const Course = mongoose.model('Course',courseSchema);
async function updateCourses(id) {
    try {
        const courses = await Course .findById(id);
        if (!courses) return;
        courses.set({name:'nedu BOss'})
        courses.save();
        console.log(courses);
    } catch(err) {
        console.log('Couldnt update any item in the mongo database');
    }
}
    
//updateCourses('45563664345677');
// if the data was imported from another database you will experience the earlier issue