NodeJs连接MongoDB以及操作方法

因为业务需要，老板就让我搞了一回MongoDB。可真是懵逼树上懵逼果，懵逼树下你和我。本着务实求知的态度，研究了下也算是搞完了。开个香槟庆祝下。

npm install mongodb-D

├─ db
│  ├─connect.js
│  └─index.js
├─ app.js
├─ ...

const MongoClient = require("mongodb").MongoClient;

const config = {
    dstHost: '127.0.0.1',
    dstPort: 42351,
}  // 数据库基本信息

var mydbname = "xxxx";  // 数据库名

function connect() {
    return new Promise((resolve, reject) => {
        // mongodb://127.0.0.1:12345/xxxxxx  连接格式
        MongoClient.connect(`mongodb://${config.dstHost}:${config.dstPort}/${mydbname}`, {
            useUnifiedTopology: true,
            maxPoolSize: 10,
            minPoolSize: 2,
            poolSize: 10
        }, function (dbConnectError, database) {
            if (dbConnectError) {
                console.error('连接失败，原因是:', dbConnectError);
                reject(dbConnectError)
            }
            const dbo = database.db(mydbname);
            console.log('连接成功！');
            resolve(dbo)  // 抛出连接实例
        });
    })
}

module.exports = connect

var connect = require("./connect");

class DB {
    constructor() {
        this.dbo = '';
        // 连接数据库，获取实例对象
        connect().then(res => {
            this.dbo = res
        })
    }
    // 增
    insert(collectionName, data) {
        return new Promise((resolve, reject) => {
            this.dbo.collection(collectionName).insertMany(data, function (error, result) {
                if (error) {
                    reject(error);
                    throw error;
                }
                resolve(result);
            });
        });
    }
    // 查
    read(collectionName, where, fields, projection, sort, limit, skip) {
        return new Promise((resolve, reject) => {
            this.dbo.collection(collectionName).find(where || {}, fields || {}).project(projection || {}).sort(sort || {}).limit(limit || 100).skip(skip || 0).toArray((error, result) => {
                if (error) {
                    reject(error);
                    throw error;
                }
                resolve(result);
            })
        })
    }
    // 改
    update(collectionName, where, data) {
        return new Promise((resolve, reject) => {
            this.dbo.collection(collectionName).updateMany(where, data, function (error, result) {
                if (error) {
                    reject(error);
                    throw error;
                }
                resolve(result);
            });
        });
    }
    // 删
    remove(collectionName, where) {
        return new Promise((resolve, reject) => {
            if (where) {
                this.dbo.collection(collectionName).deleteMany(where, function (error, result) {
                    if (error) {
                        reject(error);
                        throw error;
                    }
                    resolve(result);
                });
            }
        });
    }
    // 总
    count(collectionName) {
        return new Promise((resolve, reject) => {
            try {
                let result = this.dbo.collection(collectionName).countDocuments();
                resolve(result);
            } catch (e) {
                reject(e);
            }
        })
    }
    // 自定义数据库语句
    dbo(callback) {
        return new Promise((resolve, reject) => {
            try {
                let result = null;
                if (typeof callback === "function") {
                    result = callback(this.dbo);
                }
                resolve(result);
            } catch (e) {
                reject(e);
            }
        })
    }
}

module.exports = DB

const DB = require("../db");

var db = new DB();

// 简单使用增加方法
async insert(req, res) {
    var body = req.body
    var result = await db.insert('user', [body]);
    res.send({
        code: 200,
        msg: '成功',
        data: result
    })
}