mysql2异步/等待未定义的行和字段node.js

Question

为什么即使用户表有数据，下面的查询也会返回未定义的行和字段？我如何在打字稿中正确使用承诺版本。任何帮助将不胜感激。谢谢...

代码

import mysql from 'mysql2';
import 'dotenv/config';
import bluebird from 'bluebird';

//? this all configuration for database connection
const connection: any = mysql.createConnection({
  host: process.env.DB_HOSTNAME,
  user: process.env.DB_USER,
  database: process.env.DATABASE,
  Promise: bluebird,
});

//! test connection - required
const testConnection = async () => {
  try {
    //? output to the console the query value
    let [rows, fields]: [any, any] = await connection.execute(
      'SELECT * FROM user',
    );
    console.log(rows, fields);
    console.log('successfully connected to database');
  } catch (error) {
    console.log(error);
  }
};


testConnection();

控制台输出

undefined undefined

successfully connected to database

Answer 1

查看mysqldocs，我有两个建议：

• 我发现您需要更改导入的内容。
• 您还需要等待

  createConnection

  电话。

// get the client
const mysql = require('mysql2/promise');
 
// get the promise implementation, we will use bluebird
const bluebird = require('bluebird');
  
const testConnection = async () => {
  try {
    // create the connection, specify bluebird as Promise
    const connection = await mysql.createConnection({host:'localhost', user: 'root', database: 'test', Promise: bluebird});
    // query database
    const [rows, fields] = await connection.execute('SELECT * FROM `table` WHERE `name` = ? AND `age` > ?', ['Morty', 14]);

    console.log(rows, fields);
    console.log('successfully connected to database');
  } catch (error) {
    console.log(error);
  }
};