Thinking

這mongoose的MapReduce真的不知道是怎麼一回事，真的讓我很搞不懂，寫一篇文章來記錄 一些實驗結果，釐清倒底MapReduce with populate是怎麼運作的，先看一下Schema

``` javascript article.js var ArticleSchema = new Schema({ created: { type: Date, default: Date.now }, title: { type: String, default: “, trim: true }, content: { type: String, default: “, trim: true }, user: { type: Schema.ObjectId, ref: ‘User’ } });

我們可以看到ArticleSchema是有參考UserSchema的，那就再看一下UserSchema

``` javascript user.js
var UserSchema = new Schema({
    name: String,
    email: String,
    username: {
        type: String,
        unique: true
    },
    hashed_password: String,
    provider: String,
    salt: String,
    facebook: {},
    twitter: {},
    github: {},
    google: {},
    linkedin: {}
});