原文摘自我的前端博客,欢迎大家来访问
像我这篇文章所说的基于Node.js + jade + Mongoose 模仿gokk.tv,当时停止开发是因为我深深的感觉到当时想错了,应该用两个Schema,而不是一个下面又有数组来存,这样取数据是方便,当时分页相当麻烦,不能使用原生提供的limit方法。
今天看到一本书上有讲,尝试了一把,记录下来
我们实验的场景为一个班级有N多学生,先通过学生ID找到班级名称(是不是被玩腻了?)
先来将Schema定义好
ClazzSchema :
var mongoose = require('mongoose')
var ClazzSchema = new mongoose.Schema({
clazzName:String
})
//其他方法省略..
}
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 : studentId}).populate('clazzID')
.exec(callback)
}
//其他方法省略..
}
module.exports = StudentSchema
可以看到,主需要将ClazzID设为ref到Clazz,依赖为你建立Model时的名称就可以了,要查询Clzz使用populate
下面是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
大同小异,着重看test.js
var mongoose = require('mongoose')
var Clazz = require('./models/clazzModel')
var Student = require('./models/studentModel')
//var db = mongoose.createConnection('localhost', 'gokk')
mongoose.connect('mongodb://localhost/test')
/*var clazz = new Clazz(
{
clazzName:'软件2班'
}
);
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);
})
之前添加了两班级:软件一班和软件二班
我们在新增hacke2时将classID设为软件2班的,查新hacke2时自动就会把关键的 Class查询到
{ _id: 542b600a683d59a80d4ee632,
name: 'hacke2',
clazzID: { _id: 542b5fcc49df6e741d8d15f5, clazzName: '软件2班', __v: 0 },
__v: 0 }
end from http://www.hacke2.cn