Mongoose 更新未更新:{ ok: 0, n: 0, nModified: 0 } [英] Mongoose update not updating: { ok: 0, n: 0, nModified: 0 }

问题描述

我在 MongoDB 上有一个名为权限"的集合.我想实现一个这样的简单更新:

I have a collection named "permissions" on MongoDB. I want to implement a simple update like this:

let schema = new Schema({
    title: String
  });
  let Permissions = mongoose.model("Permission", schema);
  let permission = new Permissions();

  let query = {};
  let newValues = {
    $set: {
      title: "Yes"
    }
  };
  permission.updateOne(query, newValues, (err, docs) => {
    console.log(err); // null
    console.log(docs); // { ok: 0, n: 0, nModified: 0 }
    if (err) return cast.error(err);
    return cast.ok();
  });

但是我在 docs 的控制台日志中收到 { ok: 0, n: 0, nModified: 0 }和 null 在 err 的控制台日志中.

However I receive { ok: 0, n: 0, nModified: 0 } in console log of docs and null in console log of err.

我做错了什么?

推荐答案

根据 docs

模型是从架构定义编译的奇特构造函数.一个模型的实例称为文档.模型负责从底层 MongoDB 数据库创建和读取文档.

Models are fancy constructors compiled from Schema definitions. An instance of a model is called a document. Models are responsible for creating and reading documents from the underlying MongoDB database.

因此您只需要在 .save() 调用期间创建实例.其他操作(更新、读取、删除)应用于现有文档，因此无需创建实例.

So you need to create instance during the .save() call only. Other operations(update, read, delete) applied on the existing document and hence, no need to create instance.

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