猫鼬模式嵌入式文档默认 [英] Mongoose Schema Embedded Document Default

问题描述

我正在尝试将一个文档(因此是一个子文档)嵌入到Mongoose模式中.我一直遵循猫鼬文档建议的模式.我的架构如下所示.

I am trying embed a document, so I guess a subdocument, into a Mongoose schema. I have been following this pattern that the Mongoose documentation suggests. My schemas look like this.

var CategoriesSchema = new Schema({
    name: { type: String, required: true, default: 'default' }
});

var PostSchmea = new Schema({
    title: { type: String, required: true, default: 'default title' },
    writtenBy: { type: ObjectId, required: true, default: '55878003ebf4b06110ef2ff8' },
    publishedOn: { type: Date, default: Date.now },
    updatedOn: Date,
    published: { type: Boolean, required: true, default: false },
    content: { type: String, required: true, default: 'empty' },
    category: { type: [CategoriesSchema] },
    tags: [String],
    images: [String]
});

如您所见，我将CategoriesSchema嵌入到PostSchema中.我的问题是如何在PostSchema内为类别键设置默认值.我尝试了以下操作，并收到错误"TypeError:无法读取未定义的属性'$ __'":

As you can see I have the CategoriesSchema embedded into the PostSchema. My question is how do I set a default for the category key inside of the PostSchema. I tried the following and got the error "TypeError: Cannot read property '$__' of undefined":

var PostSchmea = new Schema({
    title: { type: String, required: true, default: 'default title' },
    writtenBy: { type: ObjectId, required: true, default: '55878003ebf4b06110ef2ff8' },
    publishedOn: { type: Date, default: Date.now },
    updatedOn: Date,
    published: { type: Boolean, required: true, default: false },
    content: { type: String, required: true, default: 'empty' },
    category: { type: [CategoriesSchema], default: [CategoriesSchema] },
    tags: [String],
    images: [String]
});

我还尝试了以下操作，并收到错误"SyntaxError:意外令牌":

And I also tried the following and got the error "SyntaxError: Unexpected token":

var PostSchmea = new Schema({
    title: { type: String, required: true, default: 'default title' },
    writtenBy: { type: ObjectId, required: true, default: '55878003ebf4b06110ef2ff8' },
    publishedOn: { type: Date, default: Date.now },
    updatedOn: Date,
    published: { type: Boolean, required: true, default: false },
    content: { type: String, required: true, default: 'empty' },
    category: { type: [CategoriesSchema], default: new CategoriesSchema(name: "default") },
    tags: [String],
    images: [String]
});

任何建议或文档将不胜感激.

Any suggestions or documentation would be greatly appreciated.

谢谢

推荐答案

我相信问题可能出在您的依赖项声明中.我使用您的代码声明了猫鼬模式，并且可以正常工作，但是您没有包括依赖项或创建方法，因此，让我向您展示如何创建记录，希望对您有所帮助.您也可以参考此Stack Overflow答案以获取ObjectId的依赖项声明:

I believe the problem might lie in your dependency declarations. I used your code to declare the mongoose schemas, and it worked correctly, however you did not include your dependencies, or your create methods, so let me show you how I created the record and I hope that helps. You can also reference this Stack Overflow answer for dependency declaration of the ObjectId: How to set ObjectId as a data type in mongoose

这是我的代码:

//contents of stackoverflow.js
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
var ObjectId = Schema.ObjectId;

var CategoriesSchema = new Schema({
    name: { type: String, required: true, default: 'default' }
});


var PostSchmea = new Schema({
   title: { type: String, required: true, default: 'default title' },
   writtenBy: { type: ObjectId, required: true, default:     '55878003ebf4b06110ef2ff8' },
   publishedOn: { type: Date, default: Date.now },
   updatedOn: Date,
   published: { type: Boolean, required: true, default: false },
   content: { type: String, required: true, default: 'empty' },
   category: { type: [CategoriesSchema], default: [CategoriesSchema] },
   tags: [String],
   images: [String]
});

mongoose.model('Post', PostSchmea);
mongoose.model('Categories',CategoriesSchema);

然后我在server.js文件中声明了模式和模型以运行代码并创建一条记录:

I then declared the Schemas and models in my server.js file to run the code and create a record:

//contents of my server.js file (or wherever you put your controllers)    
var stack = require('./app/models/stackoverflow'),
post = mongoose.model('Post');

var v = new post({
  //Define your values here
});

v.save(function(err,docs) {
if (err) {
   console.log(err)

} else {
  console.log(docs)
}
});

这成功创建了具有所有定义的默认值的记录.希望能有所帮助.

This successfully created the records with all of the defined default values. Hope that helped.

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