SQl Pool in Node.js

index.js

var sqlTable = require('./sqlTable');

function insertIntSqlTable(aThing) {
    'use strict';
    sqlTable.pool.query('INSERT INTO aTable (things) VALUES (?)', [aThing], function(err, rows, fields) {
        if (err) console.log('SQL Error: ' + err);
    });
}

sqlTable.js

var mysql = require('mysql');

var dbConnectInformation = {
    connectionLimit: 10, // Just to curb our enthusiasm.
    host: 'localhost',
    user: '<username>',
    password: '<password>',
    database: '<dtabase>',
    port: <portNumber>
};

var pool = mysql.createPool(dbConnectInformation);
exports.pool = pool;

Declaring pool above the getDbConnection function allows all users of this module to share the same pool.

Actually there is no reason not to just define the pool at creation time.
The node-mysql module will not actually connect to the DB until a query is made,
and if the DB kills off the connections, the node-mysql module will rebuild the connections
as needed up until the connection limit.