A collection of related databases mongodb

Usually there is a relationship between different sets of data, for example, in a different set, but when a user article published articles and user information storage, to query all of the information published in the article include users, you need to use a set of associations.

 

Articles collection	User Collections
_id	_id
title	name
author	age
content	hobbies

 

Example:

the require Mongoose = const ( 'Mongoose') 

mongoose.connect ( 'MongoDB: // localhost / test1', {useNewUrlParser: to true}) 
  .then (() => the console.log ( 'database connection success')) 
  .catch ( err => console.log ( 'data connection' + ERR)) 

// set of rules article 
const = PostSchema new new mongoose.Schema ({ 
  title: String, 
  Content: String, 
  author: { 
    type: mongoose.Schema.Types.ObjectId , 
    REF: 'the user' 
  } 
}) 

// user set rules 
const = UserSchema new new mongoose.Schema ({ 
  name: String, 
  Age: Number The, 
  hobbies: String 
}) 

// collection of articles 
const post = mongoose.model ( 'Post' , PostSchema) 
// user collections
User mongoose.model = const ( 'the User', UserSchema) 

// Create User 
user.create (name {: 'zhangsan', Age: 20 is, hobbies: '11111'}) 
  .then (RES => the console.log (RES )) 
  .catch (ERR => the console.log (ERR)) 

// // Create Base 
post.create ({title: 'test test', content: 'contents contents', author: '5d34f0542fdc3f7924249a9c'}) 
  . the then (RES => the console.log (RES)) 
  .catch (ERR => the console.log (ERR)) 

  // query 
post.find (). populate ( 'author '). then (res => console.log ( res))