Mongoose即使是简单的表查询
从我原来的博客尖,欢迎大家光临
像我这篇文章所说的基于Node.js + jade + Mongoose 模仿gokk.tv。当时停止开发是由于我深深的感觉到当时想错了,应该用两个Schema。而不是一个以下又有数组来存。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
})
//其它方法省略..
}
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)
}
//其它方法省略..
}
module.exports = StudentSchema
能够看到。主须要将ClazzID设为ref到Clazz,依赖为你建立Model时的名称就能够了,要查询Clzz使用populate
以下是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);
})
之前加入了两班级: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时自己主动就会把关键的 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