如何更新猫鼬中的数字数组

Question

我无法在 MongoDB (Mongoose) 中更新文档内的数组。这是我对股票模型的定义。

const ticker = new mongoose.Schema({
   ticker: String,
   Price: Number,
   Amount: Number,
   PastPrices: [Number]
});
export const stock = mongoose.model("Stocks", ticker);

这是 MongoDB

中的一份文档

{
  "_id": {
    "$oid": "61e5d0e1dfda4d7c85dc8fe2"
  },
  "PastPrices": [
    2
  ],
  "ticker": "TSLA",
  "Price": 2,
  "Amount": 0,
  "__v": 0
}

我在 mongoose 中运行并且 PastPrices 没有更新。我希望能够每隔几秒将其推送到此数组中，然后将其渲染到图表中

 stock.updateOne({ticker: "TSLA"},
        { $push: { PastPrices:1}}
    );

我没有收到任何错误，只是没有更新

Answer 1

您的查询是正确的，但是为了让查询return更新数据，您需要传递额外的配置{ new: true }。如果不传，查询会更新数据，但是会return旧数据

stock.updateOne(
  { ticker: "TSLA" },
  { $push: { PastPrices:1 } },
  { new: true }
);

Answer 2

updateOne returns a Query, which doesn't execute your update immediately. From the Mongoose guide for Queries 它指出：

A mongoose query can be executed in one of two ways. First, if you pass in a callback function, Mongoose will execute the query asynchronously and pass the results to the callback.

A query also has a .then() function, and thus can be used as a promise.

意味着你可以传递一个回调函数，就像在 documentation for executing Queries:

const Person = mongoose.model('Person', yourSchema);
// find each person with a last name matching 'Ghost', selecting the `name` and > `occupation` fields
Person.findOne({ 'name.last': 'Ghost' }, 'name occupation', function (err, person) {
 if (err) return handleError(err);
 // Prints "Space Ghost is a talk show host".
  console.log('%s %s is a %s.', person.name.first, person.name.last,
    person.occupation);
});

你也可以使用then or exec if you want to use Promises. From the Mongoose documentation for promises:

const query = Band.findOne({name: "Guns N' Roses"});
assert.ok(!(query instanceof Promise));

 // A query is not a fully-fledged promise, but it does have a `.then()`.
query.then(function(doc) {
 // use doc
});

// `.exec()` gives you a fully-fledged promise
const promise = Band.findOne({name: "Guns N' Roses"}).exec();
assert.ok(promise instanceof Promise);

promise.then(function (doc) {
  // use doc
});

如果在异步方法中，您还可以await查询：

await stock.updateOne({ticker: "TSLA"},
        { $push: { PastPrices:1}}
    );

如何更新猫鼬中的数字数组

How to update a array of numbers in mongoose

javascript

mongoose

mongodb

mongodb-query

typescript