无法使用 NodeJS 对 MySQL 事务使用 async/await

Question

我是如何在 nodejs 中使用 mysql 的初学者

所以我在 youtube 上尝试了这个基本教程并开始调整它

我正在尝试使用 async/await，以便可以在 mysql 中开始事务

这是代码

const pool = require('../../config/database')

module.exports = {
    create: async (data, callBack) => {

        const connection = await pool.getConnection();

        await connection.beginTransaction();

        try {

            await connection.query(
                `insert into user_details(fullname,gender,email,password,phone_number)
                values(?,?,?,?,?)`,
                [
                    data.fullName,
                    data.gender,
                    data.email,
                    data.password,
                    data.phone_number
                ],
                (error, results, fields) =>{
                    if(error){
                        return callBack(error);
                    }
                        return callBack(null, results);
                }
            );
            await connection.commit();

        } finally {

            connection.release();

        }
    }
}

但问题是 连接 未定义

我在const connection = await pool.getConnection(); 行之前安慰了池，它不为空。 但是在const connection = await pool.getConnection(); connection 之后是未定义的

有什么帮助吗？ :D

编辑： 致@Terry Lennox

这是日志

addUserDetails, creating connection...
addUserDetails, creating connection...
addUserDetails, starting transaction...
addUserDetails, running query...
addUserDetails, an error occurred: TypeError: Cannot read property 'fullName' of undefined
    at Object.addUserDetails [as create] (C:\Playground\nodejs-mysql\api\users\user.service.js:19:26)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:12412) UnhandledPromiseRejectionWarning: TypeError: Cannot read property 'fullName' of undefined
    at Object.addUserDetails [as create] (C:\Playground\nodejs-mysql\api\users\user.service.js:19:26)
    at process._tickCallback (internal/process/next_tick.js:68:7)
(node:12412) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:12412) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
addUserDetails, starting transaction...
addUserDetails, running query...
addUserDetails, committing transaction...
addUserDetails, transaction committed.

编辑：

这是我的 app.js

require('dotenv').config();
const express = require('express');
const app = express();
const userRouter = require('./api/users/user.router');

app.use(express.json());

app.use('/api/users', userRouter);

app.listen(process.env.PORT, ()=>{
    console.log("Server is now running");
})

这是我的 user.router.js

const userController = require('./user.controller')
const router = require('express').Router();
const {checkToken} = require('../../auth/token.validation');


router.post("/", userController.createUser);
router.get("/", checkToken, userController.getUsers);
router.get("/:id", checkToken, userController.getUserById);
router.patch("/", checkToken, userController.updateUser);
router.delete("/:id", checkToken, userController.deleteUser);
router.post("/login", userController.login)


module.exports = router;

这是我的控制器

const userService = require('./user.service');

const { genSaltSync, hashSync, compareSync} = require('bcryptjs');
const { sign } = require('jsonwebtoken');


module.exports = {
    createUser: (req,res) =>{
        const body = req.body;
        const salt = genSaltSync(10);
        body.password = hashSync(body.password, salt);
        userService.create()
        userService.create(body, (err, results)=>{
            if(err){
                console.log(err);
                return res.status(500).json({
                    success: 0,
                    message: "An error occured: "+ err
                })
            }
            return res.status(200).json({
                success: 1,
                code: results,
                data: body

            });
        })
    }
}

最后是我的 service.js

async function addUserDetails(data) {
        console.log("addUserDetails, creating connection...");
        const connection = await pool.getConnection();

        try {
            console.log("addUserDetails, starting transaction...");
            await connection.beginTransaction();

            console.log("addUserDetails, running query...");
            const queryResult = await connection.query(
                `insert into user_details(fullname,gender,email,password,phone_number) values(?,?,?,?,?)`,
                [
                    data.fullName,
                    data.gender,
                    data.email,
                    data.password,
                    data.phone_number
                ]
            );

            console.log("addUserDetails, committing transaction...");
            await connection.commit();
            console.log("addUserDetails, transaction committed.");
            return queryResult;
        } catch (error) {
            console.error("addUserDetails, an error occurred:", error);

        } finally {
            connection.release();
        }
    }

module.exports = {
create: addUserDetails
}

这也是我的泳池配置

PORT = 3000
DB_PORT = 3306
DB_HOST = localhost
DB_USER = root
DB_PASS =

Answer 1

我建议用 mysql2 试试这个，你会得到一个基于 Promise 的接口，它很好用。你也可以使用 Promise 而不是回调返回结果。

user.service：

const mysql = require('mysql2/promise');

const config = {
    host: 'some_host',
    user: 'some_user',
    password: 'some_password',
    database: 'some_db'
}

const pool = mysql.createPool(config);

async function addUserDetails(data) {

    console.log("addUserDetails, creating connection...");
    const connection = await pool.getConnection();

    try {
        console.log("addUserDetails, starting transaction...");
        await connection.beginTransaction();

        console.log("addUserDetails, running query...");
        const queryResult = await connection.query(
            `insert into user_details(fullname,gender,email,password,phone_number) values(?,?,?,?,?)`,
            [
                data.fullName,
                data.gender,
                data.email,
                data.password,
                data.phone_number
            ]
        );

        console.log("addUserDetails, committing transaction...");
        await connection.commit();
        console.log("addUserDetails, transaction committed.");
        return queryResult;
    } catch (error) {
        console.error("addUserDetails, an error occurred:", error);
        throw error;
    } finally {
        connection.release();
    }
}

module.exports = {
    create: addUserDetails
}


// Test the function.. this can all be deleted later on!
const data = { 
    fullName: "Jim Ryan",
    gender: "Male",
    email: "jim.ryan@example.com",
    password: "123",
    phone_number: "555-442"
}

async function testAddUserDetails() {
    try { 
        let results = await addUserDetails(data);
        console.error(`testAddUserDetails: results:`, results);
    } catch (error) {
        console.error(`testAddUserDetails: Error:`, error);
    }
}

testAddUserDetails();

更新的用户控制器：

用户控制器：

const userService = require('./user.service');

const { genSaltSync, hashSync, compareSync} = require('bcryptjs');
//const { sign } = require('jsonwebtoken');

module.exports = {  
    createUser: async (req, res) => {
        const body = req.body;
        const salt = genSaltSync(10);
        body.password = hashSync(body.password, salt);
        try { 
            let results = await userService.create(body);
            return res.status(200).json({
                success: 1,
                code: results,
                data: body
            });
        } catch (err) {
            console.log(err);
            return res.status(500).json({
                success: 0,
                message: "An error occured: "+ err
            })
        }
    }
}

Answer 2

你也可以和mysql一起使用，只使用这个函数，不带任何参数或回调。确保你有 async 函数并使用这些函数：

await con.rollback();
await con.beginTransaction();
await con.commit();