是否有一种方法可以将created_at和updated_at字段添加到猫鼬模式中,而不必在每次调用new MyModel()时传递它们?

created_at字段将是一个日期,仅在创建文档时添加。 每当对文档调用save()时,updated_at字段将被更新为新的日期。

我已经在我的模式中尝试了这一点,但除非我显式地添加它,否则字段不会显示:

var ItemSchema = new Schema({
    name    : { type: String, required: true, trim: true },
    created_at    : { type: Date, required: true, default: Date.now }
});

当前回答

您可以使用猫鼬部队的时间戳插件将此行为添加到任何模式。

其他回答

使用machinpack -datetime格式化日期时间。

tutorialSchema.virtual('createdOn').get(function () {
    const DateTime = require('machinepack-datetime');
    let timeAgoString = "";
    try {
        timeAgoString = DateTime.timeFrom({
            toWhen: DateTime.parse({
                datetime: this.createdAt
            }).execSync(),
            fromWhen: new Date().getTime()
        }).execSync();
    } catch(err) {
        console.log('error getting createdon', err);
    }
    return timeAgoString; // a second ago
});

Machine pack非常出色,具有清晰的API,不像express或一般的Javascript世界。

像这样向Schema添加时间戳,然后createdAt和updatedAt将自动为您生成

var UserSchema = new Schema({
    email: String,
    views: { type: Number, default: 0 },
    status: Boolean
}, { timestamps: {} });

你也可以改变createdAt -> created_at by

timestamps: { createdAt: 'created_at', updatedAt: 'updated_at' }

更新:(5年后)

Note: If you decide to use Kappa Architecture (Event Sourcing + CQRS), then you do not need updated date at all. Since your data is an immutable, append-only event log, you only ever need event created date. Similar to the Lambda Architecture, described below. Then your application state is a projection of the event log (derived data). If you receive a subsequent event about existing entity, then you'll use that event's created date as updated date for your entity. This is a commonly used (and commonly misunderstood) practice in miceroservice systems.

更新:(4年后)

如果你使用ObjectId作为你的_id字段(通常情况下),那么你所需要做的就是:

let document = {
  updatedAt: new Date(),
}

查看下面我的原始答案,了解如何从_id字段获取创建的时间戳。 如果你需要使用外部系统的id,请检查Roman Rhrn Nesterov的答案。

更新:(2.5年后)

你现在可以在猫鼬>= 4.0版本中使用#时间戳选项。

let ItemSchema = new Schema({
  name: { type: String, required: true, trim: true }
},
{
  timestamps: true
});

如果设置了时间戳,猫鼬将createdAt和updatedAt字段分配给你的模式,分配的类型是Date。

你也可以指定时间戳字段的名称:

timestamps: { createdAt: 'created_at', updatedAt: 'updated_at' }

Note: If you are working on a big application with critical data you should reconsider updating your documents. I would advise you to work with immutable, append-only data (lambda architecture). What this means is that you only ever allow inserts. Updates and deletes should not be allowed! If you would like to "delete" a record, you could easily insert a new version of the document with some timestamp/version filed and then set a deleted field to true. Similarly if you want to update a document – you create a new one with the appropriate fields updated and the rest of the fields copied over.Then in order to query this document you would get the one with the newest timestamp or the highest version which is not "deleted" (the deleted field is undefined or false`). Data immutability ensures that your data is debuggable – you can trace the history of every document. You can also rollback to previous version of a document if something goes wrong. If you go with such an architecture ObjectId.getTimestamp() is all you need, and it is not Mongoose dependent.


最初的回答:

如果你使用ObjectId作为你的身份字段,你不需要created_at字段。ObjectIds有一个叫做getTimestamp()的方法。

ObjectId("507c7f79bcf86cd7994f6c0e").getTimestamp()

这将返回以下输出:

ISODate("2012-10-15T21:26:17Z")

更多信息在这里我如何提取一个Mongo ObjectID创建的日期

为了添加updated_at文件,你需要使用这个:

var ArticleSchema = new Schema({
  updated_at: { type: Date }
  // rest of the fields go here
});

ArticleSchema.pre('save', function(next) {
  this.updated_at = Date.now();
  next();
});

从Mongoose 4.0开始,你现在可以在Schema上设置一个时间戳选项,让Mongoose为你处理这个问题:

var thingSchema = new Schema({..}, { timestamps: true });

你可以像这样更改字段的名称:

var thingSchema = new Schema({..}, { timestamps: { createdAt: 'created_at' } });

http://mongoosejs.com/docs/guide.html#timestamps

const mongoose = require('mongoose');
const config = require('config');
const util = require('util');

const Schema = mongoose.Schema;
const BaseSchema = function(obj, options) {
  if (typeof(options) == 'undefined') {
    options = {};
  }
  if (typeof(options['timestamps']) == 'undefined') {
    options['timestamps'] = true;
  }

  Schema.apply(this, [obj, options]);
};
util.inherits(BaseSchema, Schema);

var testSchema = new BaseSchema({
  jsonObject: { type: Object }
  , stringVar : { type: String }
});

现在您可以使用这个选项,这样就不需要在每个表中都包含这个选项