Mongoose Schema嵌入文檔默認

Question

我想嵌入一個文檔，所以我猜一個子文檔，到Mongoose架構。我一直遵循Mongoose documentation提出的這種模式。我的模式看起來像這樣。

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] 
}); 

正如您所看到的，我已將CategoriesSchema嵌入到PostSchema中。我的問題是如何爲PostSchema中的類別鍵設置默認值。我嘗試以下，並得到了錯誤「類型錯誤：無法讀取屬性未定義‘$ __’」：

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] 
}); 

而且我也試過以下，並得到了錯誤「語法錯誤：意外令牌」：

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] 
}); 

任何建議或文件將不勝感激。

謝謝，

Answer 1

我相信問題可能在於您的依賴聲明。我用你的代碼來聲明mongoose模式，並且它工作正常，但是你沒有包含你的依賴關係，或者你的創建方法，所以讓我告訴你我是如何創建記錄的，並且我希望這會有所幫助。您也可以參考這個堆棧溢出的答案爲的ObjectId的依賴性聲明：How to set ObjectId as a data type in mongoose

這裏是我的代碼：

//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); 

然後我宣佈我server.js文件中的架構和模式來運行代碼和創建一個記錄：

//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) 
} 
}); 

這成功創建了所有定義的默認值的記錄。希望有所幫助。