也许是时间的问题,也许是我淹没在稀疏的文档中,无法理解Mongoose中的更新概念:)

事情是这样的:

我有一个联系模式和模型(缩短属性):

var mongoose = require('mongoose'),
    Schema = mongoose.Schema;

var mongooseTypes = require("mongoose-types"),
    useTimestamps = mongooseTypes.useTimestamps;


var ContactSchema = new Schema({
    phone: {
        type: String,
        index: {
            unique: true,
            dropDups: true
        }
    },
    status: {
        type: String,
        lowercase: true,
        trim: true,
        default: 'on'
    }
});
ContactSchema.plugin(useTimestamps);
var Contact = mongoose.model('Contact', ContactSchema);

我从客户端收到一个请求,包含我需要的字段,然后使用我的模型:

mongoose.connect(connectionString);
var contact = new Contact({
    phone: request.phone,
    status: request.status
});

现在问题来了:

If I call contact.save(function(err){...}) I'll receive an error if the contact with the same phone number already exists (as expected - unique) I can't call update() on contact, since that method does not exist on a document If I call update on the model: Contact.update({phone:request.phone}, contact, {upsert: true}, function(err{...}) I get into an infinite loop of some sorts, since the Mongoose update implementation clearly doesn't want an object as the second parameter. If I do the same, but in the second parameter I pass an associative array of the request properties {status: request.status, phone: request.phone ...} it works - but then I have no reference to the specific contact and cannot find out its createdAt and updatedAt properties.

因此,我的底线是:给定一个文档联系人,如果它存在,我如何更新它,如果它不存在,我如何添加它?

谢谢你的时间。


当前回答

非常优雅的解决方案,你可以通过使用chain of Promises实现:

app.put('url', (req, res) => {

    const modelId = req.body.model_id;
    const newName = req.body.name;

    MyModel.findById(modelId).then((model) => {
        return Object.assign(model, {name: newName});
    }).then((model) => {
        return model.save();
    }).then((updatedModel) => {
        res.json({
            msg: 'model updated',
            updatedModel
        });
    }).catch((err) => {
        res.send(err);
    });
});

其他回答

我花了整整3个小时来解决同样的问题。具体来说,我想“替换”整个文档(如果它存在的话),或者以其他方式插入它。下面是解决方案:

var contact = new Contact({
  phone: request.phone,
  status: request.status
});

// Convert the Model instance to a simple object using Model's 'toObject' function
// to prevent weirdness like infinite looping...
var upsertData = contact.toObject();

// Delete the _id property, otherwise Mongo will return a "Mod on _id not allowed" error
delete upsertData._id;

// Do the upsert, which works like this: If no Contact document exists with 
// _id = contact.id, then create a new doc using upsertData.
// Otherwise, update the existing doc with upsertData
Contact.update({_id: contact.id}, upsertData, {upsert: true}, function(err{...});

我在Mongoose项目页面上创建了一个问题,要求将这方面的信息添加到文档中。

Mongoose现在支持本地findOneAndUpdate(调用MongoDB findAndModify)。

如果对象不存在,upsert = true选项将创建该对象。默认为false。

var query = {'username': req.user.username};
req.newData.username = req.user.username;

MyModel.findOneAndUpdate(query, req.newData, {upsert: true}, function(err, doc) {
    if (err) return res.send(500, {error: err});
    return res.send('Succesfully saved.');
});

在旧版本中,Mongoose不支持这些钩子:

违约 setter 验证器 中间件

非常优雅的解决方案,你可以通过使用chain of Promises实现:

app.put('url', (req, res) => {

    const modelId = req.body.model_id;
    const newName = req.body.name;

    MyModel.findById(modelId).then((model) => {
        return Object.assign(model, {name: newName});
    }).then((model) => {
        return model.save();
    }).then((updatedModel) => {
        res.json({
            msg: 'model updated',
            updatedModel
        });
    }).catch((err) => {
        res.send(err);
    });
});

对于任何到达这里仍然在寻找一个好的解决方案“upserting”与钩子支持,这是我已经测试和工作。它仍然需要2个DB调用,但比我在一次调用中尝试过的任何东西都稳定得多。

// Create or update a Person by unique email.
// @param person - a new or existing Person
function savePerson(person, done) {
  var fieldsToUpdate = ['name', 'phone', 'address'];

  Person.findOne({
    email: person.email
  }, function(err, toUpdate) {
    if (err) {
      done(err);
    }

    if (toUpdate) {
      // Mongoose object have extra properties, we can either omit those props
      // or specify which ones we want to update.  I chose to update the ones I know exist
      // to avoid breaking things if Mongoose objects change in the future.
      _.merge(toUpdate, _.pick(person, fieldsToUpdate));
    } else {      
      toUpdate = person;
    }

    toUpdate.save(function(err, updated, numberAffected) {
      if (err) {
        done(err);
      }

      done(null, updated, numberAffected);
    });
  });
}

按照旅行技术人员的回答,这已经很棒了,我们可以创建一个插件,并在初始化后将其附加到mongoose上,这样.upsert()将在所有模型上可用。

plugins.js

export default (schema, options) => {
  schema.statics.upsert = async function(query, data) {
    let record = await this.findOne(query)
    if (!record) {
      record = new this(data)
    } else {
      Object.keys(data).forEach(k => {
        record[k] = data[k]
      })
    }
    return await record.save()
  }
}

db.js

import mongoose from 'mongoose'

import Plugins from './plugins'

mongoose.connect({ ... })
mongoose.plugin(Plugins)

export default mongoose

然后您可以执行User之类的操作。upsert({_id: 1}, {foo: 'bar'})或YouModel。Upsert ({bar: 'foo'}, {value: 1})。