Item.js

import db from '../database';

class Item {
    static fetch(user_id) {
        return // make sure you return the promise so it can be seen by the outer method!
        db.query("select * from items where user_id = $1", user_id)
            .then(function (result) {
                // This result object obvs comes from the $promise.resolve(result); that would happen within query.
                // Lets pretend result is the string "Hello world"
                console.log(result);
                // prints "Hello world"
                // You can then propagate that result, or shift it or do whatever you want, or you could return it 
                // unaltered. in this case we'll return uppercased :P
                return result.toUpperCase();
            })
            .catch(function (error) {
               console.log(error)
               // Do a similar thing with the error, you can also do other things like resolve it here probs
            });
    }
}


// Now lets see what happens when we do this Item.fetch, I ceebs instantiating though but pretend I did

Item.fetch(5)
    .then(function(result) {
        console.log(result);
        // Outputs "HELLO WORLD"
    });

export default Item;

So I'm going to just show you what happens with the propagation of the promise

Also a fantastic tutorial on the ins and outs of promise, I highly recommend it alongside this code fragment http://www.html5rocks.com/en/tutorials/es6/promises/