node.js - 如何在我的 Mongoose 模式中引用另一个模式？

Question

我正在为约会应用构建 Mongoose 架构。

我希望每个 person 文档都包含对他们去过的所有事件的引用，其中 events 是另一个架构，在系统中有自己的模型。如何在架构中描述这一点？

var personSchema = mongoose.Schema({
    firstname: String,
    lastname: String,
    email: String,
    gender: {type: String, enum: ["Male", "Female"]}
    dob: Date,
    city: String,
    interests: [interestsSchema],
    eventsAttended: ???
});

Answer 1

您可以使用 Population 来描述它

Population is the process of automatically replacing the specified paths in the document with document(s) from other collection(s). We may populate a single document, multiple documents, plain object, multiple plain objects, or all objects returned from a query.

假设您的事件架构定义如下:

var mongoose = require('mongoose')
  , Schema = mongoose.Schema

var eventSchema = Schema({
    title     : String,
    location  : String,
    startDate : Date,
    endDate   : Date
});

var personSchema = Schema({
    firstname: String,
    lastname: String,
    email: String,
    gender: {type: String, enum: ["Male", "Female"]}
    dob: Date,
    city: String,
    interests: [interestsSchema],
    eventsAttended: [{ type: Schema.Types.ObjectId, ref: 'Event' }]
});

var Event  = mongoose.model('Event', eventSchema);
var Person = mongoose.model('Person', personSchema);

要展示如何使用填充，首先创建一个人对象，aaron = new Person({firstname: 'Aaron'}) 和一个事件对象，event1 = new Event({标题:'Hackathon'，位置:'foo'}):

aaron.eventsAttended.push(event1);
aaron.save(callback); 

然后，当您进行查询时，您可以像这样填充引用:

Person
.findOne({ firstname: 'Aaron' })
.populate('eventsAttended') // only works if we pushed refs to person.eventsAttended
.exec(function(err, person) {
    if (err) return handleError(err);
    console.log(person);
});