# MangoDB

**Repository Path**: guibinbin/mango-db

## Basic Information

- **Project Name**: MangoDB
- **Description**: MangoDB 学习
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2023-08-28
- **Last Updated**: 2023-08-30

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# MangoDB
## 介绍
>     分布式文件存储数据库
## 核心概念
- Mongodb
    - 数据库(database):
        - 数据库是一个数据仓库，数据库服务下可以创建很多数据库，数据库中可以存放很多集合
    - 集合(collection):
        - 集合类似于 JS 中的数组，在集合中可以存放很多文档
    - 文档(document):
        - `文档是数据库中最小单位`，类似 JS 中的对象

![1693191331721](image/README/1693191331721.png)

## 命令
```bash
1. 查看数据库
    show dbs
2. 使用数据库
    use [数据库名]
# use 创建后不显示是因为 数据库里没东西
3. 创建集合
    db.createColection('name')
4. 删除集合
    db.集合名.drop()
5. 集合改名
    db.集合名.renameCollection('name')
```

### 文档命令
![1693272154266](image/README/1693272154266.png)
#### 注意
```bash
# 修改数据
    db.colletionname.update()
    只修改第一个匹配位置的数据
```
![1693272908613](image/README/1693272908613.png)

## mongoose
>       是一个对象文档模型库
### 连接数据库
```javascript
// 安装 mongoose 
// npm i mongoose
// 导入 mongoose
const mongoose = require('mongoose')

// 连接mongodb
mongoose.connect('mongodb://127.0.0.1:27017/bilibili')

// 设置回调
mongoose.connection.on('open', () => {
    console.log('连接成功')
}) // 设置连接成功的回调
mongoose.connection.on('error', () => {
    console.log('连接失败')
    
}) // 设置连接失败的回调
mongoose.connection.on('close', () => {
    console.log('连接关闭')
    
}) // 设置连接关闭的回调

setTimeout(()=>{
    mongoose.disconnect()
}, 2000)
```
#### 注意
```javascript
/**
 * 官方建议 使用 once 而不是 on
 *      once
 *          事件回调函数只执行一次
 *      on
 */
// 设置回调
mongoose.connection.once('open', () => {
    console.log('连接成功')
}) // 设置连接成功的回调

mongoose.connection.once('error', () => {
    console.log('连接失败')
    
}) // 设置连接失败的回调

mongoose.connection.once('close', () => {
    console.log('连接关闭')
    
}) // 设置连接关闭的回调
```

### 插入文档
```javascript
// 安装 mongoose
// 导入 mongoose
const mongoose = require('mongoose')

// 连接mongodb
mongoose.connect('mongodb://root:123456@127.0.0.1:27017/')

// 设置回调
mongoose.connection.once('open', () => {
    // 创建文档结构对象
    // 设置集合中的文档的属性以及属性值的类型
    let BookSchema = new mongoose.Schema({
        name: String,
        author: String,
        price: Number
    })  
    // 创建模型对象
    // 对文档操作的封装对象          集合名称  操作对象
    let BookModel = mongoose.model('books', BookSchema)

    // 新增
    BookModel.create({
        name: '西游记',
        author: '吴承恩',
        price: 19.9
    }).then((err, data) => {
        if(err){
            console.log(err)
            return
        }
        console.log(data)
    })
}) // 设置连接成功的回调

mongoose.connection.once('error', () => {
    console.log('连接失败')
    
}) // 设置连接失败的回调

mongoose.connection.once('close', () => {
    console.log('连接关闭')
    
}) // 设置连接关闭的回调
```

```javascript
// 安装 mongoose
// 导入 mongoose
const mongoose = require('mongoose')

// 连接mongodb
mongoose.connect('mongodb://127.0.0.1:27017/')

// 设置回调
mongoose.connection.once('open', () => {
    console.log('连接成功')
    // 创建文档结构对象
    // 设置集合中的文档的属性以及属性值的类型
    let BookSchema = new mongoose.Schema({
        name: String,
        author: String,
        price: Number
    })  
    // 创建模型对象
    // 对文档操作的封装对象          集合名称  操作对象
    let BookModel = mongoose.model('books', BookSchema)

    BookModel.create({
        name: '西游记',
        author: '吴承恩',
        price: 19.9
    }).then((err, data) => {
        if(err){
            console.log(err)
            return
        }
        console.log(data)
    }).then(()=>{
        mongoose.disconnect()
    })
}) // 设置连接成功的回调

mongoose.connection.once('error', () => {
    console.log('连接失败')
    
}) // 设置连接失败的回调

mongoose.connection.once('close', () => {
    console.log('连接关闭')
}) // 设置连接关闭的回调
```

#### 出现问题
- 1. **callback** 问题
```javascript
    // 新增
    BookModel.create({
        name: '西游记',
        author: '吴承恩',
        price: 19.9
    }, (err, data) => {
        if(err){
            console.log(err)
            return
        }
        console.log(data)
    })
```
- **报错**
```javascript
/home/dev/Devlopment/node_modules/mongoose/lib/model.js:2819
    throw new MongooseError('Model.create() no longer accepts a callback');
          ^

MongooseError: Model.create() no longer accepts a callback
    at Function.create (/home/dev/Devlopment/node_modules/mongoose/lib/model.js:2819:11)
    at NativeConnection.<anonymous> (/home/dev/Devlopment/02index.js:23:15)
    at Object.onceWrapper (node:events:628:28)
    at NativeConnection.emit (node:events:514:28)
    at Connection.onOpen (/home/dev/Devlopment/node_modules/mongoose/lib/connection.js:701:8)
    at _setClient (/home/dev/Devlopment/node_modules/mongoose/lib/drivers/node-mongodb-native/connection.js:395:8)
    at NativeConnection.createClient (/home/dev/Devlopment/node_modules/mongoose/lib/drivers/node-mongodb-native/connection.js:298:3)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async NativeConnection.openUri (/home/dev/Devlopment/node_modules/mongoose/lib/connection.js:778:5)

Node.js v20.5.1
```
- **解决方案**
```javascript
    // 新增
    BookModel.create({
        name: '西游记',
        author: '吴承恩',
        price: 19.9
    }).then((err, data) => {
        if(err){
            console.log(err)
            return
        }
        console.log(data)
    })
```

##### 2. 用户权限问题
- **出问题前写法**
```javascript
mongoose.connect('mongodb://127.0.0.1:27017/')
```

- **报错**
```javascript
/home/dev/Devlopment/node_modules/mongodb/lib/cmap/connection.js:202
                callback(new error_1.MongoServerError(document));
                         ^

MongoServerError: command insert requires authentication
    at Connection.onMessage (/home/dev/Devlopment/node_modules/mongodb/lib/cmap/connection.js:202:26)
    at MessageStream.<anonymous> (/home/dev/Devlopment/node_modules/mongodb/lib/cmap/connection.js:61:60)
    at MessageStream.emit (node:events:514:28)
    at processIncomingData (/home/dev/Devlopment/node_modules/mongodb/lib/cmap/message_stream.js:124:16)
    at MessageStream._write (/home/dev/Devlopment/node_modules/mongodb/lib/cmap/message_stream.js:33:9)
    at writeOrBuffer (node:internal/streams/writable:399:12)
    at _write (node:internal/streams/writable:340:10)
    at Writable.write (node:internal/streams/writable:344:10)
    at Socket.ondata (node:internal/streams/readable:785:22)
    at Socket.emit (node:events:514:28) {
  ok: 0,
  code: 13,
  codeName: 'Unauthorized',
  [Symbol(errorLabels)]: Set(0) {}
}

Node.js v20.5.1
```

- **解决方案**
```javascript
mongoose.connect('mongodb://root:123456@127.0.0.1:27017/')
```

### 字段类型
![1693293319376](image/README/1693293319376.png)

### 字段值验证
1. 必填项
```javascript
title: {
    type: string,
    required: true // 设置必填
}
```

2. 默认值
```javascript
title: {
    type: string,
    default: '匿名' // 设置默认值
}
```

3. 枚举值
```javascript
title: {
    type: string,
    enum: ['男','女'] // 设置的值必须为数组中的值
}
```

4. 唯一值
```javascript
title: {
    type: string,
    unique: true
}
// unique 必须重建集合才有效
```

#### 举例
```javascript
let BookSchema = new mongoose.Schema({
        name: {
            type: String,
            unique: true
        },
        author: String,
        price: Number
    }) 
```

### mongoose 删除文档
```javascript
// 安装 mongoose
// 导入 mongoose
const mongoose = require('mongoose')

// 连接mongodb
mongoose.connect('mongodb://127.0.0.1:27017/')

// 设置回调
mongoose.connection.once('open', () => {
    console.log('连接成功')
    // 创建文档结构对象
    // 设置集合中的文档的属性以及属性值的类型
    let BookSchema = new mongoose.Schema({
        name: String,
        author: String,
        price: Number,
    })  
    // 创建模型对象
    // 对文档操作的封装对象          集合名称  操作对象
    let BookModel = mongoose.model('books', BookSchema)

    // BookModel.deleteOne({name:'西游记'}).then((err, data)=>{
    //     if(err){
    //         console.log('删除失败')
    //         console.log(err)
    //         return
    //     }
    //     console.log(data)
    // }).then(()=>{
    //     mongoose.disconnect()
    // })

    BookModel.deleteMany({name:'西游记'}).then((err, data)=>{
        if(err){
            console.log('删除失败')
            console.log(err)
            return
        }
        console.log(data)
    }).then(()=>{
        mongoose.disconnect()
    })
}) // 设置连接成功的回调

mongoose.connection.once('error', () => {
    console.log('连接失败')
    
}) // 设置连接失败的回调

mongoose.connection.once('close', () => {
    console.log('连接关闭')
}) // 设置连接关闭的回调
```

### mongo 更新数据库
```javascript
BookModel.updateOne({name:'西游记'},{price: 20}).then((err, data)=>{
        if(err){
            console.log('删除失败')
            console.log(err)
            return
        }
        console.log(data)
    }).then(()=>{
        mongoose.disconnect()
    })

BookModel.updateMany({name:'玉华'},{price: 20}).then((err, data)=>{
        if(err){
            console.log('删除失败')
            console.log(err)
            return
        }
        console.log(data)
    }).then(()=>{
        mongoose.disconnect()
    })
```

### mongo 读取文档
```javascript
// 查找一个
BookModel.findOne({name:'玉华'}).then((err, data)=>{
        if(err){
            console.log('删除失败')
            console.log(err)
            return
        }
        console.log(data)
    }).then(()=>{
        mongoose.disconnect()
    })

// 按 id 查询
BookModel.findById('sdfasdfasw435643').then((err, data)=>{
        if(err){
            console.log('删除失败')
            console.log(err)
            return
        }
        console.log(data)
    }).then(()=>{
        mongoose.disconnect()
    })

// 查看所有
BookModel.find({author:'利达'}).then((err, data)=>{
        if(err){
            console.log('删除失败')
            console.log(err)
            return
        }
        console.log(data)
    }).then(()=>{
        mongoose.disconnect()
    })
```

### 条件控制
![1693294711498](image/README/1693294711498.png)
![1693294726720](image/README/1693294726720.png)
![1693294743790](image/README/1693294743790.png)

### 个性化读取
![1693294788468](image/README/1693294788468.png)
![1693294799888](image/README/1693294799888.png)
![1693294831049](image/README/1693294831049.png)

### mongoose 代码模块化

## 接口的介绍
>    前后端通讯的桥梁
### RESTful API
![1693297452342](image/README/1693297452342.png)

### json-server 工具
![1693297935897](image/README/1693297935897.png)

### 会话控制
![1693298210779](image/README/1693298210779.png)