From the node.js documentation, "To have a module execute code multiple times, export a function, and call that function", you could use node.js module.export and have a single file to manage the db connections.You can find more at Node.js documentation. Let's say db.js file be like:
const mysql = require('mysql');
var connection;
module.exports = {
dbConnection: function () {
connection = mysql.createConnection({
host: "127.0.0.1",
user: "Your_user",
password: "Your_password",
database: 'Your_bd'
});
connection.connect();
return connection;
}
};
Then, the file where you are going to use the connection could be like useDb.js:
const dbConnection = require('./db');
var connection;
function callDb() {
try {
connection = dbConnectionManager.dbConnection();
connection.query('SELECT 1 + 1 AS solution', function (error, results, fields) {
if (!error) {
let response = "The solution is: " + results[0].solution;
console.log(response);
} else {
console.log(error);
}
});
connection.end();
} catch (err) {
console.log(err);
}
}