mysql.connect never returns - mysql

Question

const mysql = require('mysql');
const dbCon = mysql.createConnection({
host: "localhost",
user: "mainUser",
password: "pa55",
database: "testDB"
});
dbCon.connect(function (err) {
if (err) throw err;
console.log("Connected to DB");
});
When I run it, I see the "Connected to DB" log but the program never finishes or exits, like it's waiting for something.

Answer 1

Let's try to get the code below and save this to 'dbConnect.js' file and then run node-command:
> node dbConnect.js
you will see the result.
const mysql = require('mysql');
const dbCon = mysql.createConnection({
host: "localhost",
user: "mainUser",
password: "pa55",
database: "testDB"
});
dbCon.connect(function(err) {
if (err) {
return console.log(err.message);
}
console.log('Connected to the MySQL server.');
});
let dbCreateQuery = `
create table if not exists users(
id int primary key auto_increment,
first_name varchar(255)not null,
last_name varchar(255)not null);
`;
let dbInsertQuery = `
insert into users (first_name, last_name)
values ('john', 'smith');
insert into users (first_name, last_name)
values ('jane', 'smith');
`;
let dbSelectQuery = `
select *
from users
`;
//test of create query execute
dbCon.query(
dbCreateQuery,
function(err, results, fields) {
if (err) {
console.log(err.message); //execution error
}
else {
console.log('Table "users" has been created';
}
});
//test of insert query execute
dbCon.query(
dbInsertQuery,
function(err, results, fields) {
if (err) {
console.log(err.message); //execution error
}
else {
console.log('Table "users" has been filled';
}
});
//test of select query execute
dbCon.query(
dbSelectQuery,
function(err, results, fields) {
if (err) {
console.log(err.message);
}
else {
console.log('Data rows from table "users" has been extracted';
console.log(results); // data rows
console.log(fields); // meta of fields
}
});
/*
Also, recommended use 'end()' method for closing connection to database after running operations.
*/
dbCon.end(function(err) {
if (err) {
return console.log(err.message);
}
console.log('Close the MySQL server connection.');
});
/*
Then use 'destroy()' method for close connection immediately, it's
guarantees that no more callbacks or events will be triggered for the connection,
i.e. method does not take any callback argument like the end() method.
*/
dbCon.destroy();