How to connect sql server to app.js file? - mysql

Question

I have a folder called NEsql, located in a folder called sqlnames1. Inside the NEsql folder, I have the following files.
sqlcreatedb.js
var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "password"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
/*Create a database named "mydb":*/
con.query("CREATE DATABASE names", function (err, result) {
if (err) throw err;
console.log("Database created");
});
});
sqlcreatetable.js
var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "password",
database: "names"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
/*Create a table named "customers":*/
var sql = "CREATE TABLE people (id INT AUTO_INCREMENT PRIMARY KEY, firstName VARCHAR(255), lastName VARCHAR(255))";
con.query(sql, function (err, result) {
if (err) throw err;
console.log("Table created");
});
});
sqlinsertvalues.js
var mysql = require('mysql');
var con = mysql.createConnection({
host: "localhost",
user: "root",
password: "password",
database: "names"
});
con.connect(function(err) {
if (err) throw err;
console.log("Connected!");
var sql = "INSERT INTO people (firstName, lastName) VALUES ?";
var peoplenames = [
['Vedant', 'Apte'],
['Vedant', 'Savalajkar'],
['Vinay', 'Apte'],
['Varda', 'Apte'],
['Mihir', 'Wadekar'],
['Mihir', 'Kulkarni'],
['Eesha', 'Hazarika'],
['Eesha', 'Gupte'],
['Raunak', 'Sahu'],
['Hritvik', 'Agarwal'],
['Mahima', 'Kale'],
['Shivani', 'Sheth'],
['Arya', 'Chheda'],
['Diya', 'Shenoy']
];
con.query(sql, [peoplenames], function (err, result) {
if (err) throw err;
console.log("Number of records inserted: " + result.affectedRows);
});
});
All of these files work, as I am able to complete all the tasks and successfully receive all the corresponding console.log statements. However, I am unsure as to how I am supposed to connect these files to the app.js file located inside the sqlnames1 folder. Anyone know how to do this?
Here is my app.js file.
var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', indexRouter);
app.use('/users', usersRouter);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
next(createError(404));
});
// error handler
app.use(function(err, req, res, next) {
// set locals, only providing error in development
res.locals.message = err.message;
res.locals.error = req.app.get('env') === 'development' ? err : {};
// render the error page
res.status(err.status || 500);
res.render('error');
});
module.exports = app;

Answer 1

What you're trying to do could simply just be the content of the app.js file you could require your package there and run these functions. However if going that route is what you choose it you could store them in a variable and then use a module.export like so
variable_name = [desired content to export]
module.export = variable_name
If you'd like to go about building a database through separate files than your app.js you should look at the package sequelize. This is more along the lines of you're trying to do.
https://www.npmjs.com/package/sequelize
Responding to your comment if you are trying to build a db upon running app.js. You are again better off looking at an ORM of some sort that will do it better than the mysql package. With it you can import the db to your app.js and simply use
require('path to db')
then using the db how you see fit, but again building your db in this way will be difficult to do as you would have to run
node filename.js
for every single one, so again if not sequelize i would strongly recommend looking at another ORM that will get this job done for you much faster and easier. As soon as you run your app.js it will build and then run, the mysql package is not the best tool to use for what it seems you are trying to do.