帮我写前后端分离的文件的上传至mysql的代码

前端文件上传部分代码(假设使用jquery):

<form id="file-upload-form" enctype="multipart/form-data">
    <input type="file" name="file" id="file-input">
    <input type="button" value="上传" id="upload-button">
</form>

<script>
$(document).ready(function(){
    $("#upload-button").on("click", function(){
        var formData = new FormData($("#file-upload-form")[0]);
        $.ajax({
            url: "http://yourserver.com/upload",  // 文件上传接口地址
            type: "POST",
            data: formData,
            contentType: false,
            processData: false,
            success: function (res) {
                console.log("文件上传成功");
            },
            error: function (res) {
                console.log("文件上传失败");
            }
        });
    });
});
</script>

后端文件上传部分代码(假设使用node.js + express + multer):

var express = require('express');
var multer  = require('multer');
var mysql = require('mysql');
var app = express();

var storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, 'upload/')   // 文件上传存储路径
  },
  filename: function (req, file, cb) {
    cb(null, file.originalname)  // 保存文件名
  }
});
var upload = multer({ storage: storage });

app.post('/upload', upload.single('file'), function (req, res, next) {
  var file = req.file;
  var sql = "INSERT INTO files SET ?";
  var values = {
        filename: file.filename,
        filepath: file.path,
        filemimetype: file.mimetype
    }
  var connection = mysql.createConnection({
    host: 'yourhost',
    user: 'youruser',
    password: 'yourpassword',
    database: 'yourdatabase'
  });
  connection.connect();
  connection.query(sql, values, function (error, results, fields) {
    if (error) {
      console.log(error);
      res.status(500).json({err_code: 500 , err_msg: "文件上传失败"});
    }else{
      res.status(200).json({err_code: 0 , err_msg: "文件上传成功"});
    }
    connection.end();
  });
});

app.listen(3000, function () {
  console.log('app is listening