node21---mongoose

Posted 2020-09-23 672530440

01.js

//引包
var mongoose = require(‘mongoose‘);
//创建一个数据库连接
mongoose.connect(‘mongodb://localhost/test‘);

//创建一个Cat类。 语法mongosse.model(模型名字，Schema);
//这里省略了一步，就是schema是通过new mongoose.schema({})创建的（类工厂）。
var cc = mongoose.model(‘Cat‘, { name: String , age : Number , sex : String });
//对象
var kitty = new cc({ name: "汤姆"  , "sex" : "公猫"});
//var kitty1 = new cc({ a: "汤姆"}); 是不行的，因为schema定了。

kitty.save(function (err) {
    console.log(‘meow‘);
});

//寻找汤姆猫，将它改为8岁。
cc.find({"name":"汤姆"},function(err,result){
    console.log(result);//一条记录
    var xiaomao = result[0]; //xiaomao这个变量是一个Cat的实例
    xiaomao.age = 8;
    xiaomao.save();
});

02.js

/**
 * mongoose官网中，Guide是学习路线，API Doc是api接口。
 索引不能重复，查找快
 */
var mongoose = require(‘mongoose‘);
mongoose.connect(‘mongodb://localhost/test‘);

var db = mongoose.connection;
db.once(‘open‘, function (callback) {
    console.log("数据库成功打开");
});

//博客的结构(Schema是类的模版或者是一个创建类的工厂，他创建的类有这些属性)
var blogSchema = new mongoose.Schema({
    title:  String,
    author: String,
    body:   String,
    comments: [{ body: String, date: Date }],
    date: { type: Date, default: Date.now },
    hidden: Boolean,
    meta: {
        votes: Number,
        favs:  Number
    }
});
//这个工厂创建的类还有这个方法（对象也有）
blogSchema.methods.showInfo = function(){
    console.log(this.title);
}
//通过工厂创建一个有名类，类的名字是Blog，也可以是别的名字。
var bb = mongoose.model(‘Blog‘, blogSchema);

var blog = new bb({//Blog类的对象
    "title" : "博客测试",
    "author" : "考拉"
});

//blog.save();
blog.showInfo();

03.js

mongoose.connect(‘mongodb://localhost/test‘);

var db = mongoose.connection;
db.once(‘open‘, function (callback) {
    console.log("数据库成功打开");
});

//博客的结构（类工厂，工厂创建的类有这些属性）
var animalSchema = new mongoose.Schema({
    "name" : String,
    "type" : String
});
//工厂创建的类有这些方法（对象也有）
animalSchema.methods.zhaotonglei = function(callback){
    this.model(‘Animal‘).find({"type":this.type},callback);
}

//通过schema工厂创建一个有名的Animal类
var Animal = mongoose.model(‘Animal‘, animalSchema);
//creat是类的方法，创建对象。
Animal.create({"name":"汤姆","type":"猫"});
Animal.create({"name":"咪咪","type":"猫"});
Animal.create({"name":"小白","type":"狗"});
Animal.create({"name":"snoopy","type":"狗"});

Animal.findOne({"name":"小白"},function(err,result){
    var dog = result;//result是Animal的实例
    dog.zhaotonglei(function(err,result){
        console.log(result);
    });
});

04.js

/**
 * Created by Danny on 2015/9/29 10:18.
 */
var mongoose = require(‘mongoose‘);
mongoose.connect(‘mongodb://localhost/test‘);

var db = mongoose.connection;
db.once(‘open‘, function (callback) {
    console.log("数据库成功打开");
});

//博客的结构
var blogSchema = new mongoose.Schema({
    title:  String,
    author: String,
    body:   String,
    comments: [{ body: String, date: Date }]
});

//发表评论
blogSchema.methods.pinglun = function(obj,callback){
    this.comments.push(obj);
    this.save();
}

var Blog = mongoose.model(‘Blog‘, blogSchema);

//var blog = new Blog({
//    "title" : "哈哈哈",
//    "author" : "考拉",
//    "body" : "哈哈哈哈"
//});

//寻找一个标题是哈哈哈的博客，然后发表评论
Blog.findOne({"title":"哈哈哈"},function(err,blog){
    if(!blog){
        return;
    }
    blog.pinglun({"body":"再来一个评论","date" : new Date()});
});

05.js

/**
 * Created by Danny on 2015/9/29 10:18.
 */
var mongoose = require(‘mongoose‘);
mongoose.connect(‘mongodb://localhost/xuanke‘);

var db = mongoose.connection;
db.once(‘open‘, function (callback) {
    console.log("数据库成功打开");
});

//学生工厂
var studentSchema = new mongoose.Schema({
    "name" : String,
    "age" : Number,
    "sex" : String
});
//实例方法，涨一岁
studentSchema.methods.zhangyisui = function(){
    this.age++;
    this.save();//改变数据库，要save()
}
//学生类
var Student = mongoose.model("Student",studentSchema);

//课程工厂
var kechengSchema = new mongoose.Schema({
    "name" : String,
    "info" : String,
    "student" : [studentSchema]//课程表里面会有学生的全部json，不是外键
});
//添加学生
kechengSchema.methods.tianjiaxuesheng = function(studentObj,callback){
    this.student.push(studentObj);
    this.save(function(){
        callback();
    });
}

kechengSchema.methods.zhaoxuesheng = function(num,callback){
//要通过学生类去找，this是课程对象，
    Student.findOne({"name":this.student[num].name},function(err,result){
        callback(err,result);
    });
}
//课程类
var Kecheng = mongoose.model("Kecheng",kechengSchema);

//实例化几个学生
var xiaoming = new Student({"name":"小明","age":12,"sex":"男"});
xiaoming.save();
Student.creat({"name":"小hua","age":10,"sex":"nv"});
var shuxue = new Kecheng({
    "name" : "数学课",
    "info" : "学数学的"
});

shuxue.tianjiaxuesheng(xiaoming,function(){
    console.log("添加成功");
});

//寻找学生小明
Student.findOne({"name":"小明"},function(err,student){
    student.zhangyisui();//学生表改了，课程表没改，
});

//通过课程找学生
Kecheng.findOne({"name":"数学课"},function(err,kecheng){
    kecheng.zhaoxuesheng(0,function(err,result){
        result.zhangyisui();
        console.log(result);
    });
});