async.js

Which is the fastest method gets the query to MYSQL, and then comes back to output: console.log('queries finished', results)" Is there an even better method? Please explain your answer! Thanks! Method 1: var connection = mysql.createConnection({multipleStatements: true}); connection.query('SELECT ?; SELECT ?', [1, 2], function(err, results) { if (err) throw err; console.log('queries done', results); }); Method 2: const Db = mysql.createPool({ connectionLimit: 7, dateStrings: true, multipleStatements: true }); Db.getConnection(function(err, connection) { if(err) console.log(err); connection

When using async.waterfall within a for loop, it appears that the for loop iterates before the nested async.waterfall finishes all its steps. How can this be avoided? for(var i = 0; i < users.length; i++ ) { console.log(i) async.waterfall([ function(callback) { callback(null, 'one', 'two'); }, function(arg1, arg2, callback) { // arg1 now equals 'one' and arg2 now equals 'two' callback(null, 'three'); }, function(arg1, callback) { // arg1 now equals 'three' callback(null, 'done'); } ], function (err, result) { // result now equals 'done' console.log('done') }); } Output 0 1 2 3 4 done done done

I have been working with async.waterfall and nodejs. Its working very well but now I have a question about flow. I want to use a simple if condition in async.waterfall flow. async.waterfall([ callOne, callTwo, if(condition > 0 ) { callTest1, callTest2, }else{ callTest3, callTest4, } callThree, callFour, callFive, ], function (err, result) { if (err) { return res.status(400).jsonp({error: err}); } }); I just want to test for one condition .. If it is condition is true then run a few functions else run other functions. endif cleanup I was trying this too...one async.waterfall calling two async

I need to do the code like following: function taskFirst(k, v) { console.log(k, v); } function taskSecond(k, v) { console.log(k, v); } function run() { var g1 = "Something"; var g2 = "Something"; var g3 = "Something"; var g4 = "Something"; async.series( [ taskFirst(g1, g2), taskSecond(g3, g4) ], function(error, result){ } ); } What is the right way to pass custom variables and async.js callback function? Ali You could do something like this: function taskFirst(k, v, callback) { console.log(k, v); // Do some async operation if (error) { callback(error); } else { callback(null, result); } }

async.map(list, function(object, callback) { async.series([ function(callback) { console.log("1"); var booltest = false; // assuming some logic is performed that may or may not change booltest if(booltest) { // finish this current function, move on to next function in series } else { // stop here and just die, dont move on to the next function in the series } callback(null, 'one'); }, function(callback) { console.log("2"); callback(null, 'two'); } ], function(err, done){ }); }); Is there some way such that if function1 if booltest evaluates to true, don't move on to the next function that

I want to know how parallel execution works in async.js async = require('async') async.parallel([ function(callback){ for (var i = 0; i < 1000000000; i++) /* Do nothing */; console.log("function: 1") }, function(callback){ console.log("function: 2") } ]); In the above example, I expect obtain the output: function: 2 function: 1 but, the console throws the inverse, what is happening? thanks. You get the answer you don't expect because async launches function: 1 first and it doesn't release control back to the event loop. You have no async functions in function: 1 . Node.js is a single-threaded

I have a problem using Node JS when making synchronous calls.. Here's my problem: I have the following code: async.doWhilst(function(callback) { //some code callback(); }, function() { //make a database call and based on the results I should //return true to continue looping or false to stop here }, function(err) { //do some things when the loop finishes }) The problem is when calling the database it is asynchronous call and the loop continues before even returning the proper value. Thank you alot for your comments, I have solved the problem by move the database call to the loop code like this

I have started using Node.js as my backend for performing different operations like DB queries/ API calls, etc. I was reading about Node.js Async and decided to give it a try. It has been working for simple use cases where I want some tasks in parallel or series but somehow I have landed in a requirement where I need an optimal combination of series/parallel/waterfall techniques of Async. Use Case: I have following functions implemented with callbacks: function A(input, callback) { ... callback(err,result); } function B(input1, input2, callback) { ... callback(err,result); } function C(input,