MongoDB进阶

模式的扩展

预定义模式修饰符

var UserSchema = new mongoose.Schema({
    nickname:{
        type:String,
        default:'zhong user'   //预定义名字
    },
    regTime:{
        type:Date,
        default:Date.now   //预定义时间
    }
});

自定义setter修饰符 （数据保存之前）

var User = mongoose.model('User', {
    nickname: {
        type: String,
        trim: true //修饰符 去空格
    },
    blog:{
        type:String,
        set:function(url){   //自定义 方法
            if(!url) return url;
            if(0 !== url.indexOf("http://") && 0 !== url.indexOf("https://")){
                url = "http://" + url;
                return url;
            }
            
        }
    }
});

自定义getter修饰符 ( 取出数据之后 )

var User = mongoose.model('User', {
    blog:{
        type:String,
        get:function(url){
            if(!url) return url;
            if(0 !== url.indexOf("http://") && 0 !== url.indexOf("https://") ){
                url = "http://" + url;
                return url;
            }
        }
    }
});

模型的方法

静态方法

var BookSchema = new mongoose.Schema({  //模式
    name: String,
    isbn: Number
});

//添加 静态方法
BookSchema.statics.findByISBN = function(isbn, cb) {
    this.findOne({ isbn: isbn }, function(err, doc) {
        cb(err, doc);
    });
}

var Book = mongoose.model('Book',BookSchema);   //模型
var book = new Book({
    name:'NEAN IS FIDE',
    isbn:1314799
});

book.save(function(err){
    if(err){
        return console.log('sava is failed', err);
    }

    Book.findByISBN(1314799,function(err, doc){
        console.log('isok', err , JSON.stringify(doc))
    });

    book.print();

});

实例方法

var BookSchema = new mongoose.Schema({  //模式
    name: String,
    isbn: Number
});

//实例方法
BookSchema.methods.print = function(){
    console.log(this.name);
    console.log(this.isbn);
}

var Book = mongoose.model('Book',BookSchema);   //模型
var book = new Book({
    name:'NEAN IS FIDE',
    isbn:1314799
});

book.save(function(err){
    if(err){
        return console.log('sava is failed', err);
    }

    Book.findByISBN(1314799,function(err, doc){
        console.log('isok', err , JSON.stringify(doc))
    });

    book.print();

});

数据的校验

自定义，预定义验证器

var OrderScheme = new mongoose.Schema({
    count: {
        type: Number,
        required: true,   //预定义验证器 必须字段
        max:1000,        //预定义验证器 最大值
        min:10          //预定义验证器 最小值
    },
    status:{
        type:String,
        enum:['created', 'sucess', 'failed']
    },
    decs:{
        type:String,
        match: /book/g,      //预定义验证器 正则表达式
        validate:function(desc){     //自定义验证器
            return desc.length >= 10;
        }
    }
});

中间件

var ResellerSchema = new mongoose.Schema({
    address:String
});

//保存完成之后 后置处理中间件
ResellerSchema.post('save',function(next){
    console.log('this is save');
    next();
});

//保存之前
ResellerSchema.pre('save', true, function(next, done){
    console.log('zhiqian');
    next();
    done();
});

var Reseller = mongoose.model('Reseller', ResellerSchema);

var reseller = new Reseller({
    address:'123456'
});

reseller.save();

虚拟属性

var PersonSchema = new mongoose.Schema({
    firstName:String,
    lastName:String
});

//虚拟属性 fullName
PersonSchema.virtual('fullName').get(function(){
    return this.firstName+' '+ this.lastName; 
});

//将虚拟属性添加 到JSON.stringify() 方法里面
PersonSchema.set('toJSON',{ getters:true, virtual:true });

var Person = mongoose.model('Person', PersonSchema);

var person = new Person({
    firstName:'zhong',
    lastName:'sheng'
});

DBref

var User = mongoose.model('User', {
    username: String
});

var News = mongoose.model('News', {
    title: String,
    author: {
        type: mongoose.Schema.ObjectId,
        ref: 'User' //关联User 集合
    }
});

var user = new User({ username: 'zhong' });

var news = new News({
    title: 'congratulation',
    author: user
});

user.save(function(err) {
    if (err) {
        return console.log('so', err)
    }
    news.save(function(err) {
        if (err) {
            return console.log('so no', err)
        }
        
        // populate 指定填充字段 
        News.findOne().populate('author').exec(function(err,doc){
            console.log(JSON.stringify(doc));
        });

    });
})