Express JS how to include node-mysql object from a different file

Question

Express JS how to include node-mysql object from a different file

I want to include my mysql connection from the same file(in case I have to change sql password or anything I don't want to change in a many files).

Here is my mysql.js file:

module.exports = require('mysql').createConnection(
  {
      host     : 'localhost',
      user     : 'admin',
      password : 'xxxxxxxx',
      database : 'database'
  }

);

and I want to use like this:

var connection = require(__dirname + '/../../../mysql');
connection.connect();
.
.
.

My problem is it's working only once. When I start the server I can query without any issues, but in the second query I got the following error message in the console:

"Cannot enqueue Handshake after invoking quit."

Does anybody has an idea why not working?

mysql
node.js
express
node-mysql

Answer 1

Apparently you no longer need to call connect() after createConnection(), it'll be handled for you on query, if you like.

From the docs:

However, a connection can also be implicitly established by invoking a query:

var mysql = require('mysql'); var connection = mysql.createConnection(...);

connection.query('SELECT 1', function(err, rows) { // connected! (unless err is set) });

Depending on how you like to handle your errors, either method may be appropriate. Any type of connection error (handshake or network) is considered a fatal error, see the Error Handling section for more information.

Other than that, you may be calling connect() before calling end() on the same connection, you might want to check for that.

Answer 2

Thanks the help, but I found a solution for my problem. I just created the variables on my mysql.js file then I exported them like this:

var host = 'localhost';
module.exports.localhost = localhost;

After I can use it on another js file:

var connection = require(__dirname + '/../../../mysql');

connection.localhost;

I found it on this article: http://openmymind.net/2012/2/3/Node-Require-and-Exports/