mongoose中的静态方法和实例方法

叁歲伎倆 2021-07-26 00:55 615阅读 0赞

# 一、静态方法  #

mongoose中内置多种静态方法，如下：

*  Model.find()
 *  Model.findById()
 *  Model.findByIdAndDelete()
 *  Model.findByIdAndRemove()
 *  Model.findByIdAndUpdate()
 *  Model.findOne()
 *  Model.findOneAndDelete()
 *  Model.findOneAndRemove()
 *  Model.findOneAndUpdate()
 *  Model.updateMany()
 *  Model.updateOne()
 *  Model.deleteMany()
 *  Model.deleteOne()
 *  Model.replaceOne()

此外，还可以自己定义静态方法（常用）

结构目录

![20210301161558972.png][]

db.js

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70][]

const mongoose = require('mongoose')
     
    mongoose.connect("mongodb://127.0.0.1:27017/testdb", {useNewUrlParser:true},function (err) {
        if (err) {
            console.log(err)
            return
        }
        console.log("数据库连接成功！")
    })
    
    module.exports = mongoose;

user.js

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 1][]

var mongoose=require("./db.js")
    
    var SchemaUser = mongoose.Schema({
        name: String,
        age: Number,
        status: {
            type: Number,
            default:0
        }
    })
    
    SchemaUser.statics.findByName = function(name, cb) {
        this.find({"name": name}, (err, docs) => {
          cb(err, docs)
        })
    }
      
    module.exports = mongoose.model('User', SchemaUser, 'users')

main.js

![20210301161843604.png][]

let ModelUser = require('./model/users')
    
    ModelUser.findByName("李疆", function (err, doc) {
        console.log("找到了找到了，找到名为李疆的记录了：",doc)
    })

执行

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 2][]

# 二、实例方法 #

实例方法在工作中很少用

users.js

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 3][]

var mongoose=require("./db.js")
    
    var SchemaUser = mongoose.Schema({
        name: String,
        age: Number,
        status: {
            type: Number,
            default:0
        }
    })
    
    SchemaUser.methods.printInfo = function() {
        console.log("这个是实例方法")
    }
     
    module.exports = mongoose.model('User', SchemaUser, 'users')

main.js

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 4][]

let ModelUser = require('./model/users')
    
    let u = new ModelUser({
        name: '李疆',
        age: 22,
    })
    u.printInfo()

运行

![20210301162400669.png][]

[20210301161558972.png]: https://img-blog.csdnimg.cn/20210301161558972.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20210301162509874.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20210301161724725.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2,size_16,color_FFFFFF,t_70
[20210301161843604.png]: https://img-blog.csdnimg.cn/20210301161843604.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20210301161955685.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20210301162234418.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20210301162308837.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwMzIzMjU2,size_16,color_FFFFFF,t_70
[20210301162400669.png]: https://img-blog.csdnimg.cn/20210301162400669.png