无法连接到Node JS上的Mysql数据库

Question

我有一个处理mysql连接的类，每次访问de /cargos path /cargos它都应该带数据并关闭连接。 问题是，每次我尝试查询时，都会抛出此提示：

TypeError: conexao.query is not a function
at Cargos.getCargos (C:\work\PManager\api\src\models\cargos.model.js:8:17)
at C:\work\PManager\api\src\routes\cargos.js:8:16
at Layer.handle [as handle_request] (C:\work\PManager\api\node_modules\express\lib\router\layer.js:95:5)
at next (C:\work\PManager\api\node_modules\express\lib\router\route.js:137:13)
at Route.dispatch (C:\work\PManager\api\node_modules\express\lib\router\route.js:112:3)
at Layer.handle [as handle_request] (C:\work\PManager\api\node_modules\express\lib\router\layer.js:95:5)
at C:\work\PManager\api\node_modules\express\lib\router\index.js:281:22
at Function.process_params (C:\work\PManager\api\node_modules\express\lib\router\index.js:335:12)
at next (C:\work\PManager\api\node_modules\express\lib\router\index.js:275:10)
at expressInit (C:\work\PManager\api\node_modules\express\lib\middleware\init.js:40:5)
Connected

请注意，他说已连接到数据库，但是为什么我无法进行查询？

建立连接的类：

const mysql = require('mysql');

class Conexao {
    constructor() {
        this.connection = mysql.createConnection({
            host: 'localhost',
            user: 'root',
            password: '',
            database: 'agimplant'
        });
        this.connect()
    }
    connect() {
        this.connection.connect((err) => {
            if (!!err) {
                console.log("Não consegui me conectar, COD DE ERRO: ", err.code, ", MENSAGEM:", err.message)
            } else {
                console.log("Connected")
            }

        })
    }
}

module.exports = { Conexao }

将使用连接的类：

class Cargos {
    constructor() {

    }

    getCargos(conexao, callback) {
        console.log(conexao) // It shows me the properties of conexao
        conexao.query('select * from cargos', callback) 
    }
}
module.exports = { Cargos }

这是我称之为路线的地方：

const { Cargos } = require('../models/cargos.model')
const { Conexao } = require('../config/conexao')
module.exports = function (app) {
    app.get('/cargos', function (req, res) {
        var conexao = new Conexao()
        const cargos = new Cargos();

        cargos.getCargos(conexao, (err, result) => {
            if (err) {
                res.json(err)
            } else {
                res.json(result)
            }
        })
    });
} 

当我制作console.log（conexao）时，我看到了：

Conexao {
  connection:
   Connection {
     domain: null,
     _events: {},
     _eventsCount: 0,
     _maxListeners: undefined,
     config:
      ConnectionConfig {
        host: 'localhost',
        port: 3306,
        localAddress: undefined,
        socketPath: undefined,
        user: 'root',
        password: undefined,
        database: 'agimplant',
        connectTimeout: 10000,
        insecureAuth: false,
        supportBigNumbers: false,
        bigNumberStrings: false,
        dateStrings: false,
        debug: undefined,
        trace: true,
        stringifyObjects: false,
        timezone: 'local',
        flags: '',
        queryFormat: undefined,
        pool: undefined,
        ssl: false,
        multipleStatements: false,
        typeCast: true,
        maxPacketSize: 0,
        charsetNumber: 33,
        clientFlags: 455631 },
     _socket: undefined,
     _protocol:
      Protocol {
        domain: null,
        _events: {},
        _eventsCount: 0,
        _maxListeners: undefined,
        readable: true,
        writable: true,
        _config: [Object],
        _connection: [Circular],
        _callback: null,
        _fatalError: null,
        _quitSequence: null,
        _handshake: false,
        _handshaked: false,
        _ended: false,
        _destroyed: false,
        _queue: [],
        _handshakeInitializationPacket: null,
        _parser: [Object] },
     _connectCalled: false,
     state: 'disconnected',
     threadId: null } }

莫斯

Answer 1

您的Conexao类具有1个函数： connect() ，但没有query()函数。