将SELECT sql变量数组从一个文件发送到Node.js中的另一个文件

Question

I'm trying to module.export "rows" from this function over to anotherfile.js

"mysql.js"

const gameserverShow = function () {
    con.query(`SELECT * FROM gameservers`, (err, rows) => {
        if (err) throw err;
        return rows;
    });
 }

module.exports.gameserverShow = gameserverShow;

I tried to make a "foreach loop" into a array and send it over, but everytime I try to console.log it, it return "undefined". is there a different/correct way to do it?

"anotherfile.js"

const mysqlcon = require("./mysql.js");
      if (args[0] == 'show') {
            mysqlcon.gameserverShow();
            console.log(mysqlcon.gameserverShow.rows);
      }

Answer 1

You are doing that in a wrong way. You should first read how javascript function calls, callbacks works and how to handle async tasks in javascript. You have to handle it asynchronously with callbacks or promise. As you are using callbacks here following is basic code for that.

const gameserverShow = function (callback) {
    con.query(`SELECT * FROM gameservers`, (err, rows) => {
        if (err) callback(err);
        callback(null, rows);
    });
 }

module.exports.gameserverShow = gameserverShow;

And in Another file

const mysqlcon = require("./mysql.js");
      if (args[0] == 'show') {
            mysqlcon.gameserverShow((error, rows) => {
               console.log(rows);
            });
      }

You can search how to do that with promises. There are many questions about that here.