The post request was successful and the database data was increased, but it still returned an error

nodejs:

const express = require('express')
const router = express.Router()
const multer = require('multer')
const pool = require('../model/index')
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 });
// 查询数据
router.get('/',(req,res) => {
    try{
        let swiper = mysql.model('swiper')
        swiper.find((err,data) => {
            if(err) {
                console.log(err);
                res.send(err)
                return
            }
            console.log(data);
            res.send(data)
        })
    } catch (err) {
        console.log(err);
    }
})
router.post('/odd',upload.single('avatar'),(req,res) => {
    try {
        console.log('file', req.file);
        console.log('body', req.body);
        if(req.file) {
            pool.getConnection(function(err, connection) {
                if (err) console.log(err); // not connected!
                connection.query('insert into swiper values(0,?,?,?,?)',Object.values(arr[0]), function (error, results, fields) {
                    console.log('results',results);
                    arr = []
                    connection.release();
                  if (error) console.log(error);;
                });
            })
            // 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);
    }
})
// 修改数据
router.put('/:id',(req,res) => {
    try {
        console.log('put----请求',req.body);
        let swiper = mysql.model('swiper')
        let id = req.body.id
        let obj = {
            swi_url: req.body.swi_url,
            swi_type: req.body.swi_type,
            swi_qiyong: req.body.swi_qiyong,
            swi_time: req.body.swi_time
        }
        swiper.update(`id=${id}`,obj,(err,data) => {
            if(err) {
                console.log(err);
                res.send(err)
                return
            }
            res.send({code:200,msg:'数据修改成功！'})
        })
    } catch (err) {
        console.log(err);
        res.send(err)
    }
})
module.exports = router

Front-end error: