Mongoose覆盖了文档,而不是`$ set`字段

Question

说,我有一份文件:

{
  _id: 'some_mongodb_id',
  name: 'john doe',
  phone: '+12345678901',
}

我想更新这个文件:

.findOneAndUpdate({_id: 'some_mongodb_id'}, {name: 'Dan smith'})

结果应该是这样的:

{
  _id: 'some_mongodb_id',
  name: 'Dan smith',
}

应删除未指定的属性.

我怎么做？

Answer 1

实际上,但是由于mongoose实际上"搞乱"了更新,这实际上是你提交给常规MongoDB函数的默认操作.

因此,mongoose认为它"明智"是一种"假设"你想要$set在这里发出指令的便利方法.由于在这种情况下您实际上不想这样做,因此您可以{ overwrite: true }在传递给任何.update()方法的选项中关闭该行为:

作为一个完整的例子:

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

mongoose.Promise = global.Promise;
mongoose.set('debug',true);

const uri = 'mongodb://localhost/test',
      options = { useMongoClient: true };

const testSchema = new Schema({
  name: String,
  phone: String
});

const Test = mongoose.model('Test', testSchema);

function log(data) {
  console.log(JSON.stringify(data,undefined,2))
}

(async function() {

  try {

    const conn = await mongoose.connect(uri,options);

    // Clean data
    await Promise.all(
      Object.keys(conn.models).map( m => conn.models[m].remove({}) )
    );

    // Create a document
    let test = await Test.create({
      name: 'john doe',
      phone: '+12345678901'
    });
    log(test);

    // This update will apply using $set for the name
    let notover = await Test.findOneAndUpdate(
      { _id: test._id },
      { name: 'Bill S. Preston' },
      { new: true }
    );
    log(notover);

    // This update will just use the supplied object, and overwrite
    let updated = await Test.findOneAndUpdate(
      { _id: test._id },
      { name: 'Dan Smith' },
      { new: true, overwrite: true }
    );
    log(updated);


  } catch (e) {
    console.error(e);
  } finally {
    mongoose.disconnect();
  }

})()

生产:

Mongoose: tests.remove({}, {})
Mongoose: tests.insert({ name: 'john doe', phone: '+12345678901', _id: ObjectId("596efb0ec941ff0ec319ac1e"), __v: 0 })
{
  "__v": 0,
  "name": "john doe",
  "phone": "+12345678901",
  "_id": "596efb0ec941ff0ec319ac1e"
}
Mongoose: tests.findAndModify({ _id: ObjectId("596efb0ec941ff0ec319ac1e") }, [], { '$set': { name: 'Bill S. Preston' } }, { new: true, upsert: false, remove: false, fields: {} })
{
  "_id": "596efb0ec941ff0ec319ac1e",
  "name": "Bill S. Preston",
  "phone": "+12345678901",
  "__v": 0
}
Mongoose: tests.findAndModify({ _id: ObjectId("596efb0ec941ff0ec319ac1e") }, [], { name: 'Dan Smith' }, { new: true, overwrite: true, upsert: false, remove: false, fields: {} })
{
  "_id": "596efb0ec941ff0ec319ac1e",
  "name": "Dan Smith"
}

显示文档被"覆盖",因为我们抑制了$set本来会被插值的操作.这两个样本首先显示没有overwrite选项,它应用$set修饰符,然后"with" overwrite选项,其中传递了为"更新"传入的对象,并且不应用此类$set修饰符.

注意,这是MongoDB节点驱动程序"默认"执行此操作的方式.所以添加"隐式"的行为$set是由猫鼬完成的,除非你告诉它不要.