whats the best way to handle multiple database calls in nodejs

Question

I have a node app hitting postgres, in one of my functions I will need to be able to query many tables to get data to assemble for my json to send back. What is the best way to do this given the nature of nodejs, and I would like to avoid multiple levels of nested callbacks? I have been hunting around, but just am not grokking this concept well.

Perfectly explained in this answer http://stackoverflow.com/a/6604036/1520671 — Salman, Jul 01 '14 at 14:51
have you tried wait.for? https://github.com/luciotato/waitfor — Lucio M. Tato, Sep 04 '14 at 21:38

score 0 · Answer 1 · answered Jul 01 '14 at 14:50

It depends on your queries nature, if you need them execute one after another, or in parallel, gathering all the results/errors in one place.

Typical approach to avoid nested callback hell is to use async library (and series, parallel functions) or it's analogs.

It would be something like this:

async.parallel([
    function(callback) {
        db.query(..., callback);
    },
    function(callback) {
        db.query(..., callback);
    }
],

function(err, results) {
    // results is array containing array of results of your queries
});

Please refer to async documentation for more info and examples.

whats the best way to handle multiple database calls in nodejs

1 Answers1