Mongoose simple table connection Query

The original article is taken from my front-end blog. You are welcome to visit

Http://www.hacke2.cn

As I mentioned in this article, it is based on node. JS + Jade + mongoose mimic gokk. TV, at that time, the development was stopped because I deeply felt that I was wrong at that time. I should use two schemas instead of an array below to store them. This makes it easy to retrieve data. At that time, paging was quite troublesome, the limit method provided by native cannot be used.

Today I saw a lecture in a book. I tried it and recorded it.

The scenario of our experiment is that there are more than N students in a class, and the class name is first found through the student ID (isn't it tired ?)

Define schema first

Clazzschema:

VaR mongoose = require ('mongoose') var clazzschema = new Mongoose. Schema ({clazzname: string}) // other methods omitted...} module. Exports = clazzschema

Studentschema:

VaR mongoose = require ('mongoose') var studentschema = new Mongoose. schema ({Name: String, clazzid: {type: mongoose. schema. objectid, Ref: 'clazz '}) studentschema. statics = {findclazznamebystudentid: function (studentid, callback) {return this. findone ({_ ID: studentid00000000.populate('clazzid'0000.exe C (callback)} // other methods are omitted ..} module. exports = studentschema

As you can see, the master needs to set the clazzid to ref to clazz, and the dependency is the name of the model you created. to query clzz, use populate

Below is the model

var mongoose = require(‘mongoose‘)var ClazzSchema = require(‘../schemas/clazzSchema‘)var Clazz = mongoose.model(‘Clazz‘,ClazzSchema)module.exports  = Clazz

var mongoose = require(‘mongoose‘)var StudentSchema = require(‘../schemas/studentSchema‘)var Student = mongoose.model(‘Student‘,StudentSchema)module.exports  = Student

Look at test. js.

VaR mongoose = require ('mongoose') var clazz = require ('. /models/clazzmodel ') var student = require ('. /models/studentmodel ') // var DB = mongoose. createconnection ('localhost', 'okk') mongoose. connect ('mongodb: // localhost/test')/* var clazz = new clazz ({clazzname: 'software 2 class'}); clazz. save (function (argument) {console. log ('true') ;}); * // * var student = new student ({Name: 'hacke2', clazzid: '542b5fcc49df6e741d8d15f5 '}) student. save (function (ERR) {console. log ('true');}) */student. findclazznamebystudentid ('542b600a683d59a80d4ee632', function (ERR, student) {If (ERR) console. log (ERR); console. log (student. clazzid. clazzname );})

Two classes were added before: Software Class 1 and software class 2.

When hacke2 is added, the classid is set to software Class 2. When hacke2 is updated, the key class is automatically queried.

{_ ID: 542b600a683d59a80d4ee632, name: 'hacke2', clazzid: {_ ID: Role, clazzname: 'software 2 ban', _ V: 0}, _ V: 0}

End from http://www.hacke2.cn

Mongoose simple table connection Query