Mongoose:Coffeescript 中的递归嵌入文档

2022-01-24 00:00:00 mongodb javascript coffeescript mongoose

基于 此示例(有效):

var Comment = new Schema();

Comment.add({
    title : { type: String, index: true }
  , date : Date
  , body : String
  , comments : [Comment]
});

我想创建一个 CoffeeScript 版本

I wanted to create a CoffeeScript version

mongoose = require 'mongoose'
Schema = mongoose.Schema

Person = new Schema
Person.add
  mother: Person
  father: Person

但是它返回一个错误，我不明白为什么

However it returns an error and I don't understand why

TypeError: undefined is not a function
    at CALL_NON_FUNCTION_AS_CONSTRUCTOR (native)
    at Function.interpretAsType (/path/node_modules/mongoose/lib/schema.js:202:10)
    at Schema.path (/path/node_modules/mongoose/lib/schema.js:162:29)
    at Schema.add (/path/node_modules/mongoose/lib/schema.js:110:12)
    at Object.<anonymous> (/path/Models/test.coffee:6:10)
    at Object.<anonymous> (/path/Models/test.coffee:10:4)
    at Module._compile (module.js:411:26)
    at Object.run (/usr/local/lib/node_modules/coffee-script/lib/coffee-script.js:57:25)
    at /usr/local/lib/node_modules/coffee-script/lib/command.js:147:29
    at /usr/local/lib/node_modules/coffee-script/lib/command.js:115:26

好的，我发现当 Person 不是数组(在括号中)时它不起作用，但是为什么呢?

Okay, I found out that it doesn't work when Person isn't an array (in brackets), but why?

推荐答案

嵌入文档只能作为数组中的项存在.这是设计使然，您可以向作者询问他们的原因:)

Embedded documents can only exist as items in an array. That is by design, you can ask the authors for their reasons :)

您可能想要使用 DBRef:

Person = new Schema
  mother: { type: Schema.ObjectId, ref: 'Person' }
  father: { type: Schema.ObjectId, ref: 'Person' }

(请注意，您不需要 add 调用)

(notice you don't need the add call)

请参阅 有关填充/DBRef 的文档.

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