如何将图片从react naitve上传到mysql数据库？

import React, { useState } from 'react';
import { View, Button } from 'react-native';
import ImagePicker from 'react-native-image-picker';

const App = () => {
  const [imageData, setImageData] = useState(null);

  const selectImage = () => {
    ImagePicker.showImagePicker({}, (response) => {
      if (response.didCancel) {
        console.log('User cancelled image picker');
      } else if (response.error) {
        console.log('ImagePicker Error: ', response.error);
      } else {
        setImageData(response.data);
      }
    });
  };

  const uploadImage = () => {
    // 发送图片数据到后端
    fetch('http://your-backend-api/upload', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({ imageData }),
    })
      .then((response) => response.json())
      .then((data) => {
        console.log('Image uploaded successfully');
      })
      .catch((error) => {
        console.error('Error uploading image: ', error);
      });
  };

  return (
    <View>
      <Button title="Select Image" onPress={selectImage} />
      <Button title="Upload Image" onPress={uploadImage} />
    </View>
  );
};

export default App;

const express = require('express');
const bodyParser = require('body-parser');
const mysql = require('mysql');

const app = express();
app.use(bodyParser.json());

// 创建MySQL连接
const connection = mysql.createConnection({
  host: 'your-mysql-host',
  user: 'your-mysql-username',
  password: 'your-mysql-password',
  database: 'your-mysql-database',
});

// 处理图片上传请求
app.post('/upload', (req, res) => {
  const { imageData } = req.body;

  // 将Base64编码解码为Buffer
  const imageBuffer = Buffer.from(imageData, 'base64');

  // 将图片数据存储到MySQL数据库
  const sql = 'INSERT INTO images (data) VALUES (?)';
  connection.query(sql, [imageBuffer], (error, results) => {
    if (error) {
      console.error('Error uploading image to MySQL: ', error);
      res.status(500).json({ error: 'Failed to upload image' });
    } else {
      res.json({ success: true });
    }
  });
});

// 启动服务器
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});