Mongoose 如何更新一条数据/文档？

在Mongoose中，更新文档（通常在 MongoDB 中称为记录）可以通过几种不同的方法来实现。如果你提到的 "upstart" 文档是指需要更新的文档，那么我将展示几种在 Mongoose 中更新文档的常用方法，并提供示例。

使用 save() 方法更新文档

如果你已经查询到了一个 Mongoose 文档实例，你可以直接修改它的属性，然后调用 .save() 方法来更新它。

javascript
const mongoose = require('mongoose');
const { Schema } = mongoose;

const UserSchema = new Schema({ name: String, age: Number });
const User = mongoose.model('User', UserSchema);

async function updateUser(userId) {
  try {
    // 查询文档
    const user = await User.findById(userId);
    if (user) {
      // 修改文档的属性
      user.name = '新的名字';
      user.age = 30;

      // 保存文档
      await user.save();
      console.log('Document updated successfully');
    } else {
      console.log('Document not found');
    }
  } catch (error) {
    console.error('Error updating document:', error);
  }
}

使用 updateOne() 或 updateMany() 方法

如果你不需要先检索整个文档，你可以直接使用 updateOne() 或 updateMany() 方法来更新一个或多个文档。

javascript
async function updateUserName(userId, newName) {
  try {
    // 更新单个文档
    const result = await User.updateOne({ _id: userId }, { $set: { name: newName } });
    if (result.matchedCount === 1) {
      console.log('Document updated successfully');
    } else {
      console.log('No documents matched the query. Document not updated');
    }
  } catch (error) {
    console.error('Error updating document:', error);
  }
}

使用 findOneAndUpdate() 方法

如果你想在更新文档的同时检索更新后的文档，你可以使用 findOneAndUpdate() 方法。

javascript
async function findAndUpdateUser(userId, newName) {
  try {
    const options = { new: true }; // 返回更新后的文档
    const updatedUser = await User.findOneAndUpdate({ _id: userId }, { $set: { name: newName } }, options);
    if (updatedUser) {
      console.log('Document updated and retrieved successfully:', updatedUser);
    } else {
      console.log('Document not found');
    }
  } catch (error) {
    console.error('Error finding and updating document:', error);
  }
}

在这些示例中，我们使用了 MongoDB 的更新操作符 $set 来指定我们希望更新的字段。同时还可以使用其他更新操作符来执行更复杂的更新操作。根据你的需求，你可以选择最适合你的更新策略。

注意：确保在执行更新操作时遵循最佳实践，比如验证输入、处理错误等。

Mongoose now supports this natively with findOneAndUpdate (calls MongoDB findAndModify).

The upsert = true option creates the object if it doesn't exist. defaults to false.

shell
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.');
});

---

In older versions Mongoose does not support these hooks with this method:

• defaults
• setters
• validators
• middleware

I just burned a solid 3 hours trying to solve the same problem. Specifically, I wanted to "replace" the entire document if it exists, or insert it otherwise. Here's the solution:

shell
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{...});

I created an issue on the Mongoose project page requesting that info about this be added to the docs.

You were close with

shell
Contact.update({phone:request.phone}, contact, {upsert: true}, function(err){...})

but your second parameter should be an object with a modification operator for example

shell
Contact.update({phone:request.phone}, {$set: { phone: request.phone }}, {upsert: true}, function(err){...})

Well, I waited long enough and no answer. Finally gave up the whole update/upsert approach and went with:

shell
ContactSchema.findOne({phone: request.phone}, function(err, contact) {
    if(!err) {
        if(!contact) {
            contact = new ContactSchema();
            contact.phone = request.phone;
        }
        contact.status = request.status;
        contact.save(function(err) {
            if(!err) {
                console.log("contact " + contact.phone + " created at " + contact.createdAt + " updated at " + contact.updatedAt);
            }
            else {
                console.log("Error: could not save contact " + contact.phone);
            }
        });
    }
});

Does it work? Yep. Am I happy with this? Probably not. 2 DB calls instead of one.
Hopefully a future Mongoose implementation would come up with a Model.upsert function.

I'm the maintainer of Mongoose. The more modern way to upsert a doc is to use the Model.updateOne() function.

shell
await Contact.updateOne({
    phone: request.phone
}, { status: request.status }, { upsert: true });

If you need the upserted doc, you can use Model.findOneAndUpdate()

shell
const doc = await Contact.findOneAndUpdate({
    phone: request.phone
}, { status: request.status }, { upsert: true, useFindAndModify: false });

The key takeaway is that you need to put the unique properties in the filter parameter to updateOne() or findOneAndUpdate(), and the other properties in the update parameter.

Here's a tutorial on upserting documents with Mongoose.