一文聊聊node怎么封装mysql处理语句

npm i mysql -Snpm i express -S

const mysql = require("mysql")function createConnection() {    const connection = mysql.createConnection({        host: "",  //地址        user: "",  //用户名        password: "",  //密码        port: "",  //端口        database: ""  //数据库名    });    return connection;}module.exports.createConnection = createConnection;

const mysql = require("../mysql/mysql")let connection = null;connection = mysql.createConnection();/** * 错误消息 */let bad_msg = {    code: 500,    msg: "内部错误！"}/** * 成功消息 */let success_msg = {    code: 200,    msg: "操作成功"}const connections = {    /**     * 查询方法     * @param {*} table 表名     * @param {*} condition 条件     * @param {*} params 参数     * @param {*} search 查询条件     * @returns      */    find(table, condition, params, search = "*") {        return new Promise((resolve, reject) => {            let sql = `SELECT ${search} FROM ${table} WHERE ${condition}`            connection.query(sql, params, (err, result) => {                if (err) {                    reject(bad_msg)                } else {                    let _ = JSON.parse(JSON.stringify(success_msg))                    _.data = result                    resolve(_)                }            })        })    },    /**     * 插入方法     * @param {*} table 表名     * @param {*} condition 条件     * @param {*} params 参数     * @returns      */    insert(table, condition, params) {        return new Promise((resolve, reject) => {            const str = "?"            let _ = str.repeat((condition.split(",")).length)            let val = (Array.from(_)).toString()            let sql = `INSERT INTO ${table}(${condition}) VALUES(${val})`            connection.query(sql, params, (err, result) => {                if (err) {                    reject(bad_msg)                } else {                    resolve(success_msg)                }            })        })    },    /**     * 更新方法     * @param {*} table 表名     * @param {*} val 值     * @param {*} condition 条件     * @param {*} params 参数     * @returns      */    update(table, val, condition, params) {        return new Promise((resolve, reject) => {            let sql = `UPDATE ${table} SET ${val} WHERE ${condition}`            connection.query(sql, params, (err, result) => {                if (err) {                    reject(bad_msg)                } else {                    resolve(success_msg)                }            })        })    },    /**     * 删除方法     * @param {*} table 表名     * @param {*} condition 条件     * @param {*} params 参数     * @returns      */    del(table, condition, params) {        return new Promise((resolve, reject) => {            let sql = `DELETE FROM ${table} WHERE ${condition}`            connection.query(sql, params, (err, result) => {                if (err) {                    reject(bad_msg)                } else {                    resolve(success_msg)                }            })        })    },}module.exports = connections

const express = require("express")const router = express.Router()const connections = require("../../static/connection")// token生成插件模块const jwt = require("jsonwebtoken");// Token签名var secret = ""const CreatId = require("../../static/ranId")router.post("/user/details", (req, res) => {    connections.find("user_table", `ID=?`,req.user.ID).then(resp => {        res.send(resp)    })})router.post("/api/login", (req, res) => {    connections.find("user_table", "user=?", req.body.user).then(resp => {        let {data} = resp        if (data.length !== 0) {            for (let i = 0; i < data.length; i++) {                // 邮箱或者密码不正确的时候                if (req.body.user !== data[i].user || req.body.pwd !== data[i].pwd) {                    res.send({                        code: 202,                        msg: "用户名或密码有误!"                    })                } else {                    // 邮箱和密码输入正确                    if (req.body.user === data[i].user && req.body.pwd === data[i].pwd) {                        // 传输的token内容                        let token = jwt.sign({ ID: data[i].ID }, secret, { expiresIn: "72H" });                        // 返回结果                        res.send({                            code: 200,                            msg: "操作成功！",                            token: "Bearer " + token,                        })                    }                }            }        } else {            res.send({                code: 400,                msg: "账号不存在请注册!"            })        }    }).catch(e => {        res.send(e)    })})router.post("/api/register", (req, res) => {    connections.find("user_table", "user=?", req.body.user).then(resp => {        if (resp.data.length > 0) {            res.send({                code: 202,                msg: "该用户已经存在！"            })        } else {            let _ = req.body            let id = CreatId(3) + CreatId(3)            connections.insert("user_table", "ID,user,pwd,avatarUrl,location,RegisterTime,isAdmin,isDel", [id, _.user, _.pwd, "/static/userimg/user.webp", _.location, Date.now(), 0, 0]).then(resps => {                // 传输的token内容                let token = jwt.sign({ ID: id }, secret, { expiresIn: "72H" });                // 返回结果                res.send({                    code: 200,                    msg: "操作成功！",                    token: "Bearer " + token,                })            })        }    })})module.exports = router