开箱即用的Node.js+Mysql模块封装实现详解

├─index.js
├─db
| ├─db.js //封装的操作函数
| ├─dbconfig.js //数据库配置
| └sql.js  //sql语句

//单纯的栗子
let user = {
  insert: "INSERT INTO user(id, name, age) VALUES(?,?,?)",
  update: "UPDATE user SET name=?, age=? WHERE id=?",
  delete: "DELETE FROM user WHERE id=?",
  queryById: "SELECT * FROM user WHERE id=?",
  queryAll: "SELECT * FROM user",
};
module.exports = {
  user,
};

let MysqlConfig = {
    host: "1.2.3.4",
    user: "******",
    passWord: "******",
    port: "******",
    database: "******",
  };
module.exports = mysqlConfig

const mysql = require("mysql");
const $dbConfig = require("./dbconfig.js"); //注意改成自己项目中的路径
const sql = require("./sql.js"); 
const pool = mysql.createPool($dbConfig); // 使用连接池

let dbAdd = (table, req, res, next) => {
  return new Promise((resolve,reject)=>{
    pool.getConnection((err, connection) => {
      let paramValue = paramList(req);
      connection.query(sql[table].insert, [...paramValue], (err, result) => {
        if(err){
          reject(err)
        }
        resolve(result)
        connection.release();
      });
    });
  })
};

let dbDelete = (table, req, res, next) => {
  let paramValue = paramList(req);
  return new Promise((resolve,reject)=>{
    pool.getConnection((err, connection) => {
      connection.query(sql[table].delete, [...paramValue], (err, result) => {
        if(err){
          reject(err)
        }
        resolve(result)
        connection.release();
      });
    });
  })
};

let dbUpdate = (table, req, res, next) => {
  let paramValue = paramList(req);
  return new Promise((resolve,reject)=>{
    pool.getConnection((err, connection) => {
      connection.query(sql[table].update, [...paramValue], (err, result) => {
        if(err){
          reject(err)
        }
        resolve(result)
        connection.release();
      });
    });
  })
};

let dbQueryById = (table, req, res, next) => {
  let paramValue = paramList(req);
  return new Promise((resolve,reject)=>{
    pool.getConnection((err, connection) => {
      connection.query(sql[table].queryById, [...paramValue], (err, result) => {
        if(err){
          reject(err)
        }
        resolve(result)
        connection.release();
      });
    });
  })
};

let dbQueryAll = (table, req, res, next) => {
  return new Promise((resolve,reject)=>{
    pool.getConnection((err, connection) => {
      connection.query(sql[table].queryAll, (err, result) => {
        if(err){
          reject(err)
        }
        resolve(result)
        connection.release();
      });
    });
  })
};

let paramList = (obj) => {
  let paramArr = [];
  for (let key in obj) {
    if (obj[key]) {
      paramArr.push(obj[key]);
    }
  }
  return paramArr;
};

app.post("/login",async (req,res) =>{
  const {username,password} = req.body // 接收数据
    try {
       //看这里， 我们使用username的方式去数据库进行用户查找
      const {data} = await db.dbQueryById("user",{"username":username},res)
      // 接下来自己想象吧
    } catch (err) {
      res.JSON({
        code: "500",
        msg: "用户不存在"
      });
    }
})