gistfile1.js

I have my model here:

// transactionmodel.js
function TransactionModel() {
    var pg = require('pg');
    var connectionString = "pg://chartjes:******@localhost:5432/ibl_stats";
    this.client = new pg.Client(connectionString);
    this.client.connect();

	this.getCurrent = function(callback) {
		var startDate = "(SELECT MAX(transaction_date) FROM transaction_log)-'3 weeks'::interval)";
		var endDate = "(SELECT MAX(transaction_date) FROM transaction_log)";

		var q = "SELECT * " +
        "FROM transaction_log " +
        "WHERE log_entry LIKE 'Trades%' " +
        "AND transaction_date >= (SELECT MAX(transaction_date) FROM transaction_log)-'3 weeks'::interval " +
        "AND transaction_date <= (SELECT MAX(transaction_date) FROM transaction_log) " +
        "ORDER BY trans_id DESC ";
        var transactions = [];

        this.client.query(q, function (err, result) {
            if (err) {
                console.log(err);
                return {'success': 'false', 'msg': err};
            }

            var idx = 0;

            while (idx < result.rows.length) {
                transactionId = result.rows[idx].trans_id;
                team1 = result.rows[idx].ibl_team;
                team2 = result.rows[idx + 1].ibl_team;
                description = team1 + ' ' + result.rows[idx].log_entry;
                transactionDate = result.rows[idx].transaction_date;
                idx = idx  + 2;
                transaction = {
                    'id': transactionId,
                    'tradePartner1': team1,
                    'tradePartner2': team2,
                    'description': description,
                    'date': transactionDate
                };
                transactions.push(transaction);
            }
            callback(transactions);
        });
	};
}

module.exports.TransactionModel = TransactionModel;

and I have my "front controller" in express calling it like this:

app.get('/transactions/current', function(req, res) {
    var done = function (transactions) {
        res.send(transactions);
    };
    var currentTransactions = tm.getCurrent(done);
});

I am probably misunderstanding something fundamental here but I am wondering why I am not seeing any value in currentTransactions when I see output inside TransactionModel.getCurrent()?