猫鼬中的 Date.now() 和 Date.now 有什么区别? [英] What is the difference between Date.now() and Date.now in mongoose?

问题描述

我在猫鼬模型中使用 Date.now() 和 Date.now.

I am using Date.now() and Date.now in mongoose model.

我对它们之间的区别有点困惑.你能帮我吗?

I am a little bit confused about the difference between them. Could you please help me?

推荐答案

Date.now 可用于您的 Mongoose 架构定义中以设置字段的默认值，而 Date.now() 是等效的 JavaScript.例如，在架构定义中设置默认值时，您可以使用 Date.now.使用此架构定义，Mongoose 将使用当前时间填充 createdDate.

Date.now can be used in your Mongoose schema definition to set a default value for a field, whereas Date.now() is the JavaScript equivalent. For example, when setting a default value in your schema definition, you use Date.now. With this schema definition, Mongoose will populated createdDate with the current time.

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
//schema
var yourSchema= new Schema({
   text: {type: String},
   createdAt: {type: Date, default: Date.now}
});

但是，当针对您的架构编写 JavaScript 代码时，您必须使用 Date.now()

However, when writing JavaScript code against your schema, you have to use Date.now()

yourSchema.pre('save', function doSomething(next){
   var something = this;
   something.createdAt(Date.now());
   next();
 });

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