An error occurs occasionally when adding data to the database

Here we go again.
The problem is that the nodejs code should be fine, and the post request data can be increased, but it will say: Cannot queue handshakes after they have been queued,
nodejs code:

const express = require('express')
const router = express.Router()
const multer = require('multer')
const mysql = require('../model/orm')
let date = new Date()
const moment = require('moment')
let time = date.getTime()
let originalname;
let random = Math.floor(Math.random() * (1000 - 100 + 1)) + 100
let urlStr; 
let obj;
let arr = [];
let swi_url = ''
let storage = multer.diskStorage({
    destination: function(req, file, cb) {
        cb(null, 'public/upload'); 
    },
    filename: function(req, file, cb) {
        originalname = Buffer.from(file.originalname, "latin1").toString("utf8"); // 解决接收文件的文件名中文乱码问题
        urlStr = time + '-' + random + '-' + originalname
        time = date.getTime()
        random = Math.floor(Math.random() * (10000 - 100 + 1)) + 100
        swi_url = 'http://localhost:3000/upload/' + urlStr
        obj = {
            swi_url,
            swi_qiyong:'false',
            swi_type:"活动",
            swi_time:moment(new Date()).format()
        }
        arr.push(obj)
        cb(null, urlStr)
    }
})
let upload = multer({ storage: storage });
// 单条swiper数据增加
router.post('/odd',upload.single('avatar'),(req,res) => {
    try {
        console.log('file', req.file);
        console.log('body', req.body);
        if(req.file) {
            console.log(arr);
            let swiper = mysql.model('swiper')
            swiper.insert(arr[0],(err,data) => {
                if(err) {
                    res.send(err)
                    return 
                }
                res.status(200).send(JSON.stringify({success: '数据添加成功',code:200,swi_url:swi_url}))
            })
        } else {
            res.status(400).send(JSON.stringify({success: '服务器未接收到传递的数据或数据、格式错误'}))
        }
    } catch (err) {
        if (err instanceof multer.MulterError) {
        console.log(err.code);
        } else {
        console.log(err);
        }
        res.status(500).send(err);
    }
})

module.exports = router

Error:

Error: Cannot enqueue Handshake after already enqueuing a Handshake.
    at Protocol._validateEnqueue (c:\Users\21276\Desktop\NodeJsSquare\node_modules\mysql\lib\protocol\Protocol.js:221:16)
    at Protocol._enqueue (c:\Users\21276\Desktop\NodeJsSquare\node_modules\mysql\lib\protocol\Protocol.js:138:13)
    at Protocol.handshake (c:\Users\21276\Desktop\NodeJsSquare\node_modules\mysql\lib\protocol\Protocol.js:51:23)
    at Connection.connect (c:\Users\21276\Desktop\NodeJsSquare\node_modules\mysql\lib\Connection.js:116:18)
    at c:\Users\21276\Desktop\NodeJsSquare\model\orm.js:216:20
    at new Promise (<anonymous>)
    at Model.connect (c:\Users\21276\Desktop\NodeJsSquare\model\orm.js:215:14)
    at Model.insert (c:\Users\21276\Desktop\NodeJsSquare\model\orm.js:94:14)
    at c:\Users\21276\Desktop\NodeJsSquare\routers\swiper.js:43:20
    at Layer.handle [as handle_request] (c:\Users\21276\Desktop\NodeJsSquare\node_modules\express\lib\router\layer.js:95:5) {
  code: 'PROTOCOL_ENQUEUE_HANDSHAKE_TWICE',
  fatal: false
}

What is the problem, nodejs and database connection, I use orm, I tried to request to close the connection, but it didn't work, why, ask the big pot answer