mysql - 如何从 API Controller 中分离出 MySQL？

Question

如何将 MySQL 相关函数移至 contractsService.js 文件中？

我收到错误:

C:\code\firstdrafte2e\app.js:8 app.get('/contracts', GetContracts(req, res)); ^

ReferenceError: req is not defined

contractsService.js

exports = function GetContracts(req, res) {
    new Promise(function (resolve, reject) {
        con.connect(function (err) {
            if (err) throw err;
            con.query("SELECT * FROM " + config.DATABASE + ".Contracts", function (err, result, fields) {
                if (err) throw err;
                //console.log(result);
                resolve(result);
            });
        });
    }).then(rows => res.send(rows));
}

app.js

const express = require('express');
const app = express();


    app.use(express.static('client'));
    const config = require('./config')
    var GetContracts = require('./contractsService');

    app.get('/contracts', GetContracts());

    module.exports = app;

Answer 1

看来您没有将 (req,res) 传递给 GetContracts 函数。您可以创建一个匿名函数，分配给一个变量并将其导出，如下所示。

contractsService.js

  exports.GetContracts = function(req, res) {
new Promise(function (resolve, reject) {
    con.connect(function (err) {
        if (err) throw err;
        con.query("SELECT * FROM " + config.DATABASE + ".Contracts", function (err, result, fields) {
            if (err) throw err;
            //console.log(result);
            resolve(result);
        });
    });
}).then(rows => res.send(rows));

}

App.js

const express = require('express');
const app = express();

app.use(express.static('client'));
const config = require('./config')
var GetContracts = require('./contractsService');

app.get('/contracts', GetContracts);

module.exports = app