Develop Reference

How to create multiple object properties with a loop

I'm learning JavaScrit/node.JS and I made the code below, which checks for how many vehicles a player has stored in the database once he joins the server and spawns all them. The problem is that it only works for one vehicle right now (personalVehicles gets overwritten, I belive)
mp.events.add("playerReady", (player) => {
pool.getConnection((err, con) => {
if (err) console.log(err)
console.log()
con.query("SELECT vehicleID, vehicleModel, vehicleSpawnX, vehicleSpawnY, vehicleSpawnZ FROM vehicles WHERE vehicleType = ? AND vehicleOwner = ?", ["players", player.playerID], function (err, result) {
if (err) console.log(err)
for (i = 0; i < result.length; i++) {
vehicleModel = result[i].vehicleModel
player.personalVehicles = mp.vehicles.new(parseInt(vehicleModel), new mp.Vector3(result[i].vehicleSpawnX, result[i].vehicleSpawnY, result[i].vehicleSpawnZ))
}
});
con.release()
});
});
I've tried switching player.personalVehicles withplayer.personalVehicles.vehicle[i], player.personalVehicles.vehicle and player.personalVehicles.[i], but none of them worked.
I pretend to do something like this automatically:
player = {
personalVehicles = {
vehicle1 = xxxxxxx
vehicle2 = xxxxxxx
vehicle3 = xxxxxxx
and so on
}
}
I know it only works for one vehicle because when I try to destroy the player's vehicles once he leaves only one vehicle gets destroy (the last one in the database).
Thanks.

const obj = {};
you cannot do this obj['hits']['hits'] ='whyDosntWork'; due to obj['hist'] does not exists.
You need to do:
obj['hits'] = {}
and then obj['hits']['hits'] ='whyDosntWork';
And the same for the rest...
I cannot understand what do you want to do here:
obj['hits']['hits'][i]['_source.ActiveChannelReleases'][0]['ImageExports'][0]['Resolutions'][0]['Url']
But follow what I said before, you need to create each step the value you want. I can assume that you want an array in ´hits`

How to use multiple callbacks when looping data

I'm trying to get HTML form data, loop it through, change it a bit and insert it to database. I have tried like below app.js.
How can I make callbacks so that formdata what I have modified is available for .create function?
I have searched from everywhere and I always end up in dead end and undefined variable somehow.
app.js:
//Find the day where to save
Day.findById(req.params.id, function(err, day) {
if (err) {
console.log(err);
res.redirect("/diary");
} else {
// Search function to find data with _id
function ingredientIdQuery(reqBodyId) {
var ingQuery = Ingredient.find({_id:reqBodyId});
return dbQuery;
}
// This loops through HTML formdata and formats it for mongoose model
for (var i = 0; i < req.body.amount.length; i++) {
if (req.body.amount[i] !== "") {
var amount = Number(req.body.amount[i]);
var singleMealTempObj = {};
singleMealTempObj.amount = amount;
var _id = req.body.id[i];
var query = ingredientIdQuery(_id);
// Executing the query for the data I need with id
query.exec(function(err, ingr){
if(err) {
return console.log(err);
} else {
singleMealTempObj.ingredient = ingr[0];
singleMealTempArr.push(singleMealTempObj);
}
});
}
}
}
// This inserts data into day
Meal.create(singleMealTempArr, function(err, singleMealObject) {
if (err) {
console.log(err);
} else {
day.meals.push(singleMealObject);
day.save();
res.redirect("/day/" + day._id + "/dayshow");
}
});
});
});
Edit:
Thanks for reply and notices! While I was trying to do everything to get this work I missed those few things like declaring variables. Sorry for that. I threw the towel in to the cage at this point.
flow goes like this:
User sends HTML form data to app.js which is inside object of two arrays (id[] and amount[]). Amount array needs to be looped through if it has value other than 0. Same index id array value is used to fetch data from database. This data what is found from database with id from id[] is used with same index amount[] and it should be saved to mongo.
I can get the values from HTML form ok. but I have tried to make a search in Mongo in a for loop (query.exec in the code) I get the data ok. When I log the data outside the database query, variable is undefined.
I hope this clarifys a bit what I'm trying to achieve.
I'll continue this later... :)

I guess issue originates because of this function.
function ingredientIdQuery(reqBodyId) {
var ingQuery = Ingredient.find({_id:reqBodyId});
return dbQuery;
}
Is find function asynchronous or synchronous?
Also you are returning dbQuery but dbQuery does not seem to be changed inside the function.

Couple I noticed that may fix this:
You never define singleMealTempArr, so when you try to push data to it, you are gonna run into problems.
Your ingredientIdQuery function returns dbquery - which also isn't defined. You actually call it ingQuery. Even so...are you positive that this will return the data that you want?
// lets loop through all the form fields in req.body.amount
for (var i = 0; i < req.body.amount.length; i++) {
// keep going unless the form field is empty
if (req.body.amount[i] !== "") {
// assign all the form fields to the following vars
var amount = Number(req.body.amount[i]);
var singleMealTempObj = {};
singleMealTempObj.amount = amount;
var _id = req.body.id[i];
var query = ingredientIdQuery(_id);
// we are executing the ingredientIdQuery(_id), better
// double-check that this query returns the result we are
// looking for!
query.exec(function(err, ingr){
if(err) {
return console.log(err);
} else {
singleMealTempObj.ingredient = ingr[0];
// now that we've gone through and mapped all the form
// data we can assign it to the singleMealTempArr
// WOOPS! Looks like we forgot to assign it!
singleMealTempArr.push(singleMealTempObj);
}
});
}
}
}

Multiple MongoDB queries without using a loop?

I'm trying to figure out if I can make my MongoDB queries (fron Node.js) more quicker and more efficient.
Basically I have an array of "Players", each Player has a "player_id" property. I want to iterate over each Player and use the player_id to find data about the Player in a MongoDB database.
Because of the Asynchronous nature of Node.js I have to guarantee that when I send in a query to the database, the data that I get back corresponds to the player_id that was used to query.
So far I have the following code (that I simplified). What I'm most interested in is how I can achieve this without using a for loop. Thanks.
var playersArray = new Array({"player_id":1234567}, {"player_id":9847621}, {"player_id":0946783}, {"player_id":8712890});
queryDataForPlayers(playersArray, function(data){
//Done - Each Player now has a "new_data_property" property
})
function queryDataForPlayers(playersArray){
var newPlayersArray = new Array();
var counter = 0;
for(var i=0; i<playersArray.length; i++)
{
retrievePlayerData(playersArray[i].player_id, playersArray[i], function(err,data)
{
newPlayersArray.push(data);
if(++counter == playersArray.length)
{
callback(newPlayersArray);
}//end if
});
}
}
var Schema = mongoose.model('Schema');
var ObjectID = require('mongodb').ObjectID;
function retrievePlayerData(playerID, obj, callback){
Schema.find({_id:ObjectID(String(playerID))}, function(err,data){
obj["new_data_property"] = data;
callback(err,obj);
});
}

I can't really test this, but you can pass in an array of player ID's directly to mongo, and get a document set with the related data back in just one query, something like
var playersArray = new Array({"player_id":1234567}, {"player_id":9847621}, {"player_id":0946783}, {"player_id":8712890});
var Schema = mongoose.model('Schema');
var ObjectID = require('mongodb').ObjectID;
function queryDataForPlayers(playersArray, callback){
var player_ids = playersArray.map(function(player) {
return ObjectID(String(player.player_id));
});
Schema.find({
'_id': { $in: player_ids}
}, function(err, docs){
callback(err, docs);
});
}

Use $in operator... You can use it like
Schema.find({_id:{$in:[array_of_playerid]} }).exec(function(error,results)){
}

Ways to do a dynamic query in node.js

I'm trying to figure out how to do dynamic queries in node.js with node-mysql. Which table and fields to insert and update is based on users' request from the data object. I thought of creating a module to store different queries like the following but no luck. It gave me this error:
TypeError: Object function (){
var likes = 'INSERT IGNORE INTO item (id,like_type) VALUES(?,?)';
return likes;
} has no method 'replace'
app.js
var queries = require('./queries');
.....
socket.on("like",function(data){
var table_file = data[0].table;
var d = data[1];
connection.query(queries[table_file]
,[d.id,d.like_type],function(err,rows,fields){
if(err){ throw err;}
console.log(rows);
});
queries.js:
module.exports = {
item_like:function(){
var likes = 'INSERT IGNORE INTO item (id,like_type) VALUES(?,?)';
return likes;
},
people:function(){
var likes = 'INSERT IGNORE INTO people (id,like_type) VALUES(?,?)';
return likes;
}
}
Here's the data object sent to socket:
data object: {table:item_like},{id:1,like_type:1};

Change your exports in queries.js to be set to the SQL strings instead of functions, since that is how you're treating them currently:
module.exports = {
item_like: 'INSERT IGNORE INTO item (id,like_type) VALUES(?,?)',
people: 'INSERT IGNORE INTO people (id,like_type) VALUES(?,?)'
}

cannot pass javascript values from query to websocket

I use nodejs 0.10.12 and node-postgre 2.2.0
I created a function with two different queries in it, that they execurte fine and return results.
After the queries execute I want to gather all the results from both queries and send them to the client via websockets.
I cannot pass the values from the queries to the websockets. In the client , when I alert the incoming data I get "undifined". I though to set the vars as globals, but still nothing
Any ideas?
Thanks in advance
This is the code
//set all vars as globals, at the start of the doc
var mnm=[]; var name;
//inside the function
//query 1
client.connect();
var query = client.query('SELECT pins.p_name FROM pins WHERE pins.p_id ='+eoid)
query.on("row", function (row, result) {result.addRow(row);});
query.on("end", function (result) {
for (var i=0; i<result.rows.length; i++)
{name = result.rows[0].p_name;}
});
//query 2
var query2 = client.query('SELECT m_name FROM multi WHERE m_pins ='+eoid)
query2.on("row", function (row, result) {result.addRow(row);});
query2.on("end", function (result) {
for (var i=0; i<result.rows.length; i++)
{mnm.push(result.rows[i].m_name);}
client.end();
});
//so , now gather "name" from the first query and "mnm" from the second and send them to client
connection.send(JSON.stringify({name:name , mnm:mnm}));
EDIT
Now I realised that If I execute this code for the first time, client alerts undifined. For the second, alerts the data of the previous object I selected. if I click object1 i get undifined. If I click object 2 I get object1. Please advice

Based on Mathieu 'OtaK' Amiot's simple but effective idea , I make the second query in the "end" event of the first one.
So here is the code
client.connect();
var query = client.query('SELECT pins.p_name FROM pins WHERE pins.p_id ='+eoid)
query.on("row", function (row, result) {result.addRow(row);});
query.on("end", function (result) {
for (var i=0; i<result.rows.length; i++)
{name = result.rows[0].p_name;}
var query2 = client.query('SELECT m_name FROM multi WHERE m_pins ='+eoid)
query2.on("row", function (row, result) {result.addRow(row);});
query2.on("end", function (result) {
for (var i=0; i<result.rows.length; i++)
{mnm.push(result.rows[i].m_name);}
connection.send(JSON.stringify({name:name , mnm:mnm}));
client.end();
});//inner query "on end"
}); //outter query "on end"
Thanks Mathieu for the amazing idea. Works fine now.