nodejs api插入到数据库，但发送响应0

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

// 创建HTTP服务器
const server = http.createServer((req, res) => {
  // 解析请求数据
  bodyParser.json()(req, res, () => {
    // 连接数据库
    const connection = mysql.createConnection({
      host: 'localhost',
      user: 'username',
      password: 'password',
      database: 'database_name'
    });

    connection.connect((err) => {
      if (err) {
        console.error('Error connecting to database: ' + err.stack);
        res.statusCode = 500;
        res.end('Database connection error');
        return;
      }

      // 插入数据
      const data = req.body;
      const query = 'INSERT INTO table_name SET ?';
      connection.query(query, data, (err, result) => {
        if (err) {
          console.error('Error inserting data: ' + err.stack);
          res.statusCode = 500;
          res.end('Data insertion error');
          return;
        }

        // 处理插入结果
        if (result.affectedRows > 0) {
          res.statusCode = 200;
          res.end('1'); // 插入成功，发送响应1
        } else {
          res.statusCode = 200;
          res.end('0'); // 插入失败，发送响应0
        }
      });

      // 关闭数据库连接
      connection.end();
    });
  });
});

// 监听端口
server.listen(3000, () => {
  console.log('Server is running on port 3000');
});