Sequelize JS/Bluebird: Starting with async parallel DB calls

Question

Sequelize JS/Bluebird: Starting with async parallel DB calls

I have a question.

I wanted to start 2 db calls and then continue the promise chain.

A rather hackish way i did was to start the promise like this:

db.Model.find().then(function() { 
    return [ 
        firstcall, 
        secondcall
    ]
}).spread(function(resultFromFirstCall, resultFromSecondCall) {
    //do something once both calls completed
});

Is it alright to start the promise chain with an empty db call? Or is there a better way.

I know I can bring in that async library but I see this as a cleaner approach, if there are no performance effect to making the empty db.Model.find() call.

node.js
bluebird
sequelize.js

Answer 1

I'm not sure what an empty find call would do here since I have never used SequelizeJS, however I'm pretty sure that what you're looking for is probably Promise.join

Promise.join( firstCall, secondCall, function( firstResult, secondResult ) {
  // Whatever
});

Answer 2

After some time, I found a even better way to do it.

Promise.resolve().then(function() {
    return [
        firstCall(),
        secondCall()
    ];
}).spread(function(resultFromFirst, resultFromSecond) {
    //do something with resultFromFirst and resultFromSecond
});