Mydoc

外观

MongoDB ​

一、相关概念 ​

MongoDB是文档型的NoSQL数据库。

image-20220508194905648

image-20220507220553150

优点：

  1. 高性能

  2. 高可用性

  3. 可扩展分片集群

应用场景：（数据量大、读写操作频繁、对事务要求不高）

二、数据库操作 ​

查看所有数据库

sh
show databases
show dbs
#连接数据库后默认在test库
use testdb01 	#切换数据库
show databases
show dbs
#连接数据库后默认在test库
use testdb01 	#切换数据库

image-20220507215028603

创建/删除数据库

shell
use 数据库名 	# use testdb01
db 	#查看所在数据库
db.dropDatabase() 	#删除当前所在库
use 数据库名 	# use testdb01
db 	#查看所在数据库
db.dropDatabase() 	#删除当前所在库

三、集合相关操作 ​

shell
show collections; 	# 查看数据库集合	show tables;
db.createCollection('collectionName',[option]);	 #显式创建集合
db.users.insert({'name':'李四'}); 	#隐式创建集合 往不存在的集合插入数据
db.users.drop(); 	#删除集合
show collections; 	# 查看数据库集合	show tables;
db.createCollection('collectionName',[option]);	 #显式创建集合
db.users.insert({'name':'李四'}); 	#隐式创建集合 往不存在的集合插入数据
db.users.drop(); 	#删除集合

四、文档相关操作 ​

1.查询 ​

shell
db.users.find() 	#查询所有 SELECT * from users  
db.getCollection('users').find()	#查询所有
db.getCollection('users').findOne()	#查询第一个
db.getCollection('users').findOne({name:'zhang3'})		#查询符合条件的第一个

db.users.find( { name: 1, age: 1 } ) 	#SELECT _id,name,age from users 
db.users.find( {  name: 1, age: 1, _id: 0 } ) 	#去除id字段
db.users.find( { name: 0, age: 0 } ) 	#去除特定字段
db.users.find().pretty() 	#格式化查询(适用于长/复杂数据)
db.users.find() 	#查询所有 SELECT * from users  
db.getCollection('users').find()	#查询所有
db.getCollection('users').findOne()	#查询第一个
db.getCollection('users').findOne({name:'zhang3'})		#查询符合条件的第一个

db.users.find( { name: 1, age: 1 } ) 	#SELECT _id,name,age from users 
db.users.find( {  name: 1, age: 1, _id: 0 } ) 	#去除id字段
db.users.find( { name: 0, age: 0 } ) 	#去除特定字段
db.users.find().pretty() 	#格式化查询(适用于长/复杂数据)
  • 等值查询
shell
db.users.find( { age:18} )
#	WHERE age = 18
db.users.find( { age:18} )
#	WHERE age = 18
  • AND条件
shell
db.users.find( { age: { $lt: 30 } ,sex:'男',} )
#	WHERE sex = "男" AND age < 30
db.users.find( { age:24, age: { $lt: 30 } } )  #相同字段and查询中出现多次,以最后一个为查询条件
#	WHERE age < 30
db.users.find( { age: { $lt: 30 } ,sex:'男',} )
#	WHERE sex = "男" AND age < 30
db.users.find( { age:24, age: { $lt: 30 } } )  #相同字段and查询中出现多次,以最后一个为查询条件
#	WHERE age < 30
  • OR条件
shell
db.users.find( { $or: [{sex:'男'}, { age: { $lt: 30 } } ] } )
#	WHERE sex = "男" OR age < 30
db.users.find( { $or: [{sex:'男'}, { age: { $lt: 30 } } ] } )
#	WHERE sex = "男" OR age < 30
  • 同时使用AND和OR条件
shell
db.users.find( {
    { like:'美女'},
     $or: [{sex:'男'}, { age: { $lt: 30 } },{ name: /^p/ } ] 
} )
#	WHERE like = "美女" AND (sex = "男" OR age < 30 OR name LIKE "%p%")
db.users.find( {
    { like:'美女'},
     $or: [{sex:'男'}, { age: { $lt: 30 } },{ name: /^p/ } ] 
} )
#	WHERE like = "美女" AND (sex = "男" OR age < 30 OR name LIKE "%p%")
  • 查询条件中使用查询操作符
shell
db.users.find( { age: { $in: [ "20", "22" ] } } )
db.users.find( { age: { $in: [ "20", "22" ] } } )
  • 模糊查询
shell
db.users.find( { name:/张/} ) #查询名字中含有'张'的所有
# WHERE name LIKE "%张%
db.users.find( { name:/张/} ) #查询名字中含有'张'的所有
# WHERE name LIKE "%张%
  • 数组中的查询
shell
db.users.find(likes:{$size:3})	#查询'喜好'数组大小为3
db.users.find(likes:{$size:3})	#查询'喜好'数组大小为3
  • 排序
shell
db.users.find().sort({age:-1}) # 1 升序 	-1 降序 (没有这个字段的数据排在前面)
db.users.find().sort({age:-1}) # 1 升序 	-1 降序 (没有这个字段的数据排在前面)
  • 分页
shell
db.users.find().skip(40).limit(30) # 跳过40条数据查30条数据 (起始0,则从40开始)
db.users.find().skip(40).limit(30) # 跳过40条数据查30条数据 (起始0,则从40开始)
  • 条数
shell
db.users.find().count()
db.users.find().count()
  • 去重
shell
db.users.find().distinct('字段')
db.users.find().distinct('字段')
  • 对比语法:

image-20220507231641824

2.插入 ​

  • 单条文档
shell
db.users.insert({'name':'李四',age:18,sex:'男'});  # 提示已弃用
db.getCollection('users').insert({'name':'李四',age:18,sex:'男'})
db.users.insertOne({'name':'赵六'})
db.users.insert({'name':'李四',age:18,sex:'男'});  # 提示已弃用
db.getCollection('users').insert({'name':'李四',age:18,sex:'男'})
db.users.insertOne({'name':'赵六'})
  • 多条文档
shell
db.users.insert([{name:'缘一'},{name:'二楞'}])
db.users.insertMany([{name:'缘一1'},{name:'二楞1'}])
db.getCollection('users').insertMany([{name:'zhang3',age:19},{name:'zhang4',age:19}])
db.users.insert([{name:'缘一'},{name:'二楞'}])
db.users.insertMany([{name:'缘一1'},{name:'二楞1'}])
db.getCollection('users').insertMany([{name:'zhang3',age:19},{name:'zhang4',age:19}])
  • 脚本方式
shell
for(let i =0;i<5;i++){ 
	db.users.insert({id:i,name:'zhang'+i})
}
for(let i =0;i<5;i++){ 
	db.users.insert({id:i,name:'zhang'+i})
}

3.删除 ​

shell
db.users.remove({}) 	#删除所有文档
db.users.remove({_id:ObjectId("62767f841f41a9d7de748124")})	 #删除某一条
db.users.remove({age:20})	 #删除满足条件的数据

db.getCollection('users').deleteOne({name:'zhang3'})	 #删除某一条
db.getCollection('users').deleteMany({age:18})	 #删除满足条件的数据
db.users.remove({}) 	#删除所有文档
db.users.remove({_id:ObjectId("62767f841f41a9d7de748124")})	 #删除某一条
db.users.remove({age:20})	 #删除满足条件的数据

db.getCollection('users').deleteOne({name:'zhang3'})	 #删除某一条
db.getCollection('users').deleteMany({age:18})	 #删除满足条件的数据

4.更新 ​

语法 :

js
db.集合名称.update(
	<query>,
    <update>,
    {
        updert:<boolean>, 
        multi:<boolean>,
    	writeConcern:<document> //抛出异常的级别
    }
)
db.集合名称.update(
	<query>,
    <update>,
    {
        updert:<boolean>, 
        multi:<boolean>,
    	writeConcern:<document> //抛出异常的级别
    }
)
shell
db.users.update({_id:ObjectId('627686574f57a31b328b63ab')},{$set:{age:24,likes:['代码','吃饭']}})  #指定更新
db.users.update({age:18},{$set:{age:24,likes:['动漫','美女']}})  #更新匹配到的第一条
db.users.update(
    {age:18},
    {$set:{age:24,likes:['动漫','美女']}},
    {multi:true} 	#更新多条
    {upsert:true} 	#不存在则插入
)  #更新匹配到的所有

db.getCollection('users').update({age:18},{$set:{age:24,likes:['动漫','美女']}})	#更新匹配到的第一条
db.users.update({_id:ObjectId('627686574f57a31b328b63ab')},{$set:{age:24,likes:['代码','吃饭']}})  #指定更新
db.users.update({age:18},{$set:{age:24,likes:['动漫','美女']}})  #更新匹配到的第一条
db.users.update(
    {age:18},
    {$set:{age:24,likes:['动漫','美女']}},
    {multi:true} 	#更新多条
    {upsert:true} 	#不存在则插入
)  #更新匹配到的所有

db.getCollection('users').update({age:18},{$set:{age:24,likes:['动漫','美女']}})	#更新匹配到的第一条

五、Mongoose学习 ​

1.插入 ​

js
exports.register = async (req,res,next)=>{
  try {
     let user = new User(req.body.user)
     await user.save() 
     //转化为json才能移除密码
     user = user.toJSON()
     delete user.password
     res.send({
       msg:'注册成功!',
       user
     });
  } catch (error) {
    next(error)
  }
}
exports.register = async (req,res,next)=>{
  try {
     let user = new User(req.body.user)
     await user.save() 
     //转化为json才能移除密码
     user = user.toJSON()
     delete user.password
     res.send({
       msg:'注册成功!',
       user
     });
  } catch (error) {
    next(error)
  }
}

2.删除 ​

js
exports.deleteArticle = async (req,res,next)=>{
  try {
    let id = mongoose.Types.ObjectId(req.body.id)
    const result = await Article.findByIdAndRemove(id)
    console.log('result: ', result);
    res.succ({
      msg:'文章删除成功!'
    })
  } catch (error) {
    res.errs(error)
  }
}
exports.deleteArticle = async (req,res,next)=>{
  try {
    let id = mongoose.Types.ObjectId(req.body.id)
    const result = await Article.findByIdAndRemove(id)
    console.log('result: ', result);
    res.succ({
      msg:'文章删除成功!'
    })
  } catch (error) {
    res.errs(error)
  }
}

3.更新 ​

js
exports.updateArticle =async (req,res,next)=>{
  const article = req.body.article
  try {
    let {_id:id,title,desc,body,tagList} = req.body.article 
    
    let article  = await  Article.findByIdAndUpdate(id, { $set:req.body.article},  {new:true})
      res.succ({
        msg:'文章更新成功!',
        article:article
      })
  } catch (error) {
    res.errs(error)
  }
}
exports.updateArticle =async (req,res,next)=>{
  const article = req.body.article
  try {
    let {_id:id,title,desc,body,tagList} = req.body.article 
    
    let article  = await  Article.findByIdAndUpdate(id, { $set:req.body.article},  {new:true})
      res.succ({
        msg:'文章更新成功!',
        article:article
      })
  } catch (error) {
    res.errs(error)
  }
}

4.查询 ​

js
//获取一个文章

exports.getArticleById = async (req,res,next)=>{
  try {
      //映射用户
    const article = await Article.findById(req.params.articleId).populate('author')
    if(!article){
     return  res.errs('文章不存在!')
    }
    res.succ({
      msg:'文章查询成功!',
      article
    })
  } catch (error) {
    res.errs(error)
  }
}
//获取一个文章

exports.getArticleById = async (req,res,next)=>{
  try {
      //映射用户
    const article = await Article.findById(req.params.articleId).populate('author')
    if(!article){
     return  res.errs('文章不存在!')
    }
    res.succ({
      msg:'文章查询成功!',
      article
    })
  } catch (error) {
    res.errs(error)
  }
}
js
// 获取文章列表
exports.getArticles = async (req,res,next)=>{
  try {
   const {limit=20,offset=0,tag ,author,favorited,sortBy}  = req.body.conditions  || {}
    const filter = {}
    if(tag){
      filter.tagList = tag
    }
    //某个作者的文章
    if(author){
      const user = await User.findOne({username:author})
        filter.author =user? user._id:null;
    }
    const articleList = await Article.find(filter).skip(Number.parseInt(offset))
    .limit(Number.parseInt(limit)).sort({creeateAt:-1,...sortBy})

    const articleCount = await Article.find(filter).skip(offset).limit(limit).count()
    const totalCount = await Article.countDocuments()
    if(!articleList){
     return  res.errs('暂无文章!')
    }
    res.succ({
      msg:'文章查询列表成功!',
      articleList,
      articleCount,
      totalCount
    })
  } catch (error) {
    res.errs(error)
  }
}
// 获取文章列表
exports.getArticles = async (req,res,next)=>{
  try {
   const {limit=20,offset=0,tag ,author,favorited,sortBy}  = req.body.conditions  || {}
    const filter = {}
    if(tag){
      filter.tagList = tag
    }
    //某个作者的文章
    if(author){
      const user = await User.findOne({username:author})
        filter.author =user? user._id:null;
    }
    const articleList = await Article.find(filter).skip(Number.parseInt(offset))
    .limit(Number.parseInt(limit)).sort({creeateAt:-1,...sortBy})

    const articleCount = await Article.find(filter).skip(offset).limit(limit).count()
    const totalCount = await Article.countDocuments()
    if(!articleList){
     return  res.errs('暂无文章!')
    }
    res.succ({
      msg:'文章查询列表成功!',
      articleList,
      articleCount,
      totalCount
    })
  } catch (error) {
    res.errs(error)
  }
}

5.模型 ​

📝model/index.js

js
const mongoose = require('mongoose');
const { dbUri  } = require('../config/config.default')
mongoose.connect(dbUri);

const db = mongoose.connection;

db.on('error', console.error.bind(console, 'MongDB数据库连接失败!'));

db.once('open', function() {
  console.log('MongDB数据库连接成功!');
});
const Cat = mongoose.model('Cat', { name: String });

module.exports = {
  User:mongoose.model('User',require('./user')),
  Article:mongoose.model('Article',require('./article')),
}
const mongoose = require('mongoose');
const { dbUri  } = require('../config/config.default')
mongoose.connect(dbUri);

const db = mongoose.connection;

db.on('error', console.error.bind(console, 'MongDB数据库连接失败!'));

db.once('open', function() {
  console.log('MongDB数据库连接成功!');
});
const Cat = mongoose.model('Cat', { name: String });

module.exports = {
  User:mongoose.model('User',require('./user')),
  Article:mongoose.model('Article',require('./article')),
}

📝model/base.js

js
//基础模型 
module.exports =  {
  createAt:{
    type:Date,
    default:Date.now
  },
  updtedAt:{
    type:Date,
    default:Date.now
  }
}
//基础模型 
module.exports =  {
  createAt:{
    type:Date,
    default:Date.now
  },
  updtedAt:{
    type:Date,
    default:Date.now
  }
}

📝model/user.js

js

const mongoose =  require('mongoose')
const baseSchema = require('./base')
const md5 = require('../util/md5')
//用户模型
const userSchema = new mongoose.Schema({
  ...baseSchema,
  username:{
    type:String,
    required:true
  },
  password:{
    type:String,
    required:true,
    set:value => md5(value),
    select:false,
  },
  email:{
    type:String,
    required:true
  },
  bio:{
    type:String,
    default:null
  },
  image:{
    type:String,
    default:null
  },
  
})
module.exports = userSchema

const mongoose =  require('mongoose')
const baseSchema = require('./base')
const md5 = require('../util/md5')
//用户模型
const userSchema = new mongoose.Schema({
  ...baseSchema,
  username:{
    type:String,
    required:true
  },
  password:{
    type:String,
    required:true,
    set:value => md5(value),
    select:false,
  },
  email:{
    type:String,
    required:true
  },
  bio:{
    type:String,
    default:null
  },
  image:{
    type:String,
    default:null
  },
  
})
module.exports = userSchema

📝model/article.js

js
 const mongoose =  require('mongoose')
const Schema = mongoose.Schema
const baseSchema = require('./base')
//文章模型
const articleSchema = new mongoose.Schema({
  ...baseSchema,
  title:{
    type:String,
    required:true
  },
  desc:{
    type:String,
    required:true
  },
  body:{
    type:String,
    required:true
  },
  favoritesCount:{
    type:Number,
    default:0
  },
  tagList:{
    type:[String],
    default:null
  },
   author:{
     type:Schema.Types.ObjectId,
     ref:'User',
     required:true,
   }
})
module.exports = articleSchema
 const mongoose =  require('mongoose')
const Schema = mongoose.Schema
const baseSchema = require('./base')
//文章模型
const articleSchema = new mongoose.Schema({
  ...baseSchema,
  title:{
    type:String,
    required:true
  },
  desc:{
    type:String,
    required:true
  },
  body:{
    type:String,
    required:true
  },
  favoritesCount:{
    type:Number,
    default:0
  },
  tagList:{
    type:[String],
    default:null
  },
   author:{
     type:Schema.Types.ObjectId,
     ref:'User',
     required:true,
   }
})
module.exports = articleSchema