It is a tricky one. I thought I could use $in, but after querying, it wasn't where I was looking for.
This is my schema
var gameSchema = new mongoose.Schema({
state: {
type: String,
default: "invited"
},
finished: {
type: Boolean,
default: false
},
players: {
type: [{
type: mongoose.Schema.Types.ObjectId,
ref: 'users'
}],
required: true,
},
scores: [scoreSchema],
chat : [chatSchema]
});
The request I'm trying to make is the following, I send a user Id, if the players array contains this Id, return the other id (the array will always have length 2) in the array.
The context is that you can lookup against whom you have played before.
This is what I had, but "players" should be an array and it's not games that I want to return, so
exports.getFriends = function(id, cb){
gameSchema.find({ id: { "$in": "players"} }, function(err, games){
if(err){
return cb(err, null);
}
else{
return cb(null, games);
}
});
};
Can you try this?
exports.getFriends = function(id, cb){
gameSchema.find({ players: id }, function(err, games) {
if (err) {
return cb(err);
}
const players = games.map(game => game.players);
const mergedPlayers = [].concat.apply([], players);
const mappedPlayers = mergedPlayers.map(String); // convert ObjectIds to strings for comparisons.
const idString = String(id);
const filteredPlayers = mappedPlayers.filter(player => player !== idString);
const uniquePlayers = filteredPlayers.filter((player, index, arr) => arr.indexOf(player) === index);
return cb(null, uniquePlayers);
});
};
I'm operating under the assumption that you want an array of the unique player ids that are not the player id you passed in. I kept the vars split apart instead of chaining all of the array methods, in an attempt to improve readability.
Related
Here I am trying to modify my data over the iteration and send some result to API call.
The API Call receives a request with a structured data format which is
{ list: [{ id: "1", name: "Hello" }, ... ] }
Somehow I managed to call the API with single data ( const params in my current code, it only accepts single data).
But now it has to be done with multiple data something like this:
{ list: [{ id: "1", name: "Hello" }, { id: "22", name: "Ed" }, { id: "36", name: "Jason" } ... ] }
Here is my current code
const [table, setTalbe] = useState(..); // assume, we have some table data here
const processNow = () => {
let id = 0;
let name = '';
// if table length is greater than 1, we go for the loop.
if (table.length >= 1) {
table.map(data => {
id = data.userId;
name = data.userName;
});
//insert table data to params, here I want to add whole table data into "list"
//the final result of this list should be something like this
//ex ) list: [{ id: '123', name: 'Josh' }, { id: '125', name: 'Sue' }, { id: '2222', name: 'Paker' } ...],
// but how??
const params: any = {
list: [
{
id: id,
name: name
},
],
};
//send PUT reqeust with params
axios
.put(
'/api/v1/tosent',
params,
)
.then(res => {
console.log('The response', res);
})
.catch(err => {
console.log('The error: ', err);
});
}
};
but I'm stuck with it, please help me to finish this code to work properly.
need your kind advice.
Array.prototype.map returns a new array with the function you pass applied to every element. You should study the MDN documentation on map to understand its use.
Your current code does nothing with the map return value:
table.map(data => {
id = data.userId;
name = data.userName;
});
You probably assumed .map would mutate the data, as in change it in place. Instead, the whole operation returns a new array.
It looks like you want to do:
const list = table.map(data => {
return {
id: data.userId,
name: data.userName
}
});
This is applying a function to every element in the array that will map each element to a new object, matching your question, with an id and name key. Then it looks like you want to pass the returned value of map (which we named list above) to your call:
const params: any = {
list: list
};
Env: NodeJS service using aws-sdk for interacting with DynamoDb.
Problem: When I set an attribute of an item to an array, it is saved as a string. I expect x: ['1'] but I get x: '1'. I believe this is because I'm incorrectly writing my UpdateExpression/ExpressionAttributeValues.
Situation: I have a table with a field called users. Users is an array of uuids that can be updated. An example of an item in the table:
{ x_name: 'Hello',
owner: '123456',
x_uuid: '1357911',
users: []
}
I want to update the users array with a user uuid. To my update function I pass through:
{ users: ['13245395'] }
The update function (data is { users: ['13245395'] }):
updateX(data, { x_uuid }) {
if (!x_uuid) {
throw new Error('No x_uuid supplied')
}
// new doc client
const docClient = new AWS.DynamoDB.DocumentClient();
var params = {
TableName: this.table,
Key: {
'x_uuid': x_uuid
},
UpdateExpression: "set users = :users",
ExpressionAttributeValues:{
":users": `${data.users}`
},
ReturnValues:"ALL_NEW"
};
return new Promise((resolve, reject) =>
docClient.update(params, (error, x) => {
return error ? reject(error) : resolve(x)
})
)
}
}
The result I get is
{ x_name: 'Hello',
owner: '123456',
x_uuid: '1357911',
users: '13245395'
}
but what I expected was:
{ x_name: 'Hello',
owner: '123456',
x_uuid: '1357911',
users: ['13245395']
}
Previously tried:
wrapping data.users in an array when creating params (works for the first id but the second id added gets appended to the same string as the first so it looks like ['123,456'] instead ['123', '456'].
UpdateExpression: "set users = :users",
ExpressionAttributeValues:{
":users": [${data.users}]
},
Using the "L" and "S" data types to determine that it's an array of strings, i.e.
UpdateExpression: "set users = :users",
ExpressionAttributeValues:{
":users": { "L": { "S":${data.users} } }
},
You are converting your users array to a string
":users": `${data.users}`
Try
":users": data.users
This will set users to the array in data.users
// importing required builtin modules
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/mydb');
// schema for email
var emailSchema = mongoose.Schema({
_id: mongoose.Schema.Types.ObjectId,
html: String,
text: String,
headers: {},
subject: String,
references: [String],
messageId: String,
inReplyTo: [String],
priority: String,
from: [],
replyto: [String],
to: [],
date: Date,
receivedDate: Date,
attachments: [],
read: { type: Boolean, default: 0 },
createdAt: { type: Date, default: Date.now },
updatedAt: { type: Date, default: Date.now },
active: { type: Boolean, default: 1 },
labels: [String]
});
// schema for thread
var threadSchema = mongoose.Schema({
threadedEmails: [{ type: String, ref: 'Email' }],
createdAt: { type: Date, default: Date.now },
updatedAt: { type: Date, default: Date.now }
});
// defining models
var Email = mongoose.model('Email', emailSchema);
var Thread = mongoose.model('Thread', threadSchema);
module.exports = Email;
module.exports = Thread;
// function to return an array which contains yet anohter array of emails each representing a thread
function doCalls() {
threads = [];
// a promise that always resolves
return new Promise(function (resolve, reject) {
resolve(1);
})
// this returns the threads as expected
.then(function (result) {
return Promise.resolve(
Thread.find({}, { threadedEmails: 1, _id: 0 }).then(
(_threads) => { return _threads }, //resolve
(err) => { reject(err); } //reject
)
)
})
// this does not returns the emails array as i expect
.then(function (threads) {
allEmails = [];
threads.forEach(thread => {
// Start off with a promise that always resolves
var sequence = Promise.resolve();
sequence = sequence.then(function (result) {
console.log('then of first foreach');
//query to make a database call to get all the emails whoes messageId's matchs
query = Email.find({ messageId: { "$in": thread.threadedEmails } });
query.exec((err, result) => {
if (err) throw err;
allEmails.push(result); //but this does not works because the code execution moves ahead
console.log(result); //this console log returns the value
});
})
})
//----------------- this is the problematic code here this array returns empty ----------------//
console.log(allEmails);
})
}
doCalls()
.then(function (allEmails) {
// console.log(allEmails);
});
I have written comments where ever i feel is required in the code, even though let me explain that context of what I am trying
I am fetching from a collection named threads all the threads which goes successfully
after that I am trying to fetch all the emails from a collection named email using a database query the output of which i am trying to store inside an array called allEmails
if i console.log() it in .then() just after the database call it does gives me the output,
my question is how do I get this out ?
I want an array which contains yet another array each having a collection of emails(each representing a thread) from emails collection
hope I made it clear, if there is anything else I require to provide please be my guide and tell me.
The forEach block finishes before any of the async operations inside it return. Thus , your allEmails array will still be empty when you console.log it.
What you need to do is build an array of promises that resolve with the "result" and then feed this array into Promise.all(arrayOfPromises) which will resolve when all your promises are resolved.
Promise.all is kind enough to resolve with the array of results for you.
Your last then would look something like:
.then(function (threads) {
const promiseArray = [];
threads.forEach(thread => promiseArray.push(
Promise.resolve(Email.find({ messageId: { "$in": thread.threadedEmails } }))
)
);
return Promise.all(promiseArray);
}
That being said, for what you're trying to achieve, Model.aggregate() would be a much more elegant solution.
Hope this helps
I have two collections set up at the moment. One collection lists all of the products in my store. The other collection stores the ratings on a scale of 1-5. The ratings store in the ratings collection successfully, and the products are stored and listed successfully. However, I am attempting to reference the appropriate rating for the individual product that is listed. I am using an ng-repeat to list all of the products in my product database. I'm not sure what is going on, but my reference to the ratings is returning an empty array.
How can I get the ratings to show for each product?
Product Schema:
var mongoose = require('mongoose');
var productSchema = new mongoose.Schema({
title: {
type: String,
unique: true,
required: true,
index: true
},
description: {
type: String,
required: true
},
price: {
type: Number,
required: true,
min: 0,
},
rating: [{
type: mongoose.Schema.Types.ObjectId,
ref: 'Rating'
}],
image: {
type: String,
required: true
}
});
module.exports = mongoose.model('Product', productSchema);
Product Controller (just the read portion):
var Product = require('../models/Product');
module.exports = {
read: function (req, res) {
Product.find(req.query)
.populate('Rating')
.exec(function (err, result) {
if (err) { return res.status(500).send(err);}
console.log("this is in the product ctrl", result);
{res.send(result);}
});
},
};
Rating Schema:
var mongoose = require('mongoose');
var ratingSchema = new mongoose.Schema({
rating: {
type: Number,
enum: [1, 2, 3, 4, 5]
}
});
module.exports = mongoose.model('Rating', ratingSchema);
Rating Controller (just read and create shown):
var Rating = require('../models/Rating');
module.exports = {
create: function (req, res) {
var newRating = new Rating(req.body);
newRating.save(function (err, result) {
if (err) return res.status(500).send(err);
else res.send(result);
});
},
read: function (req, res) {
Rating.find(req.query)
.populate('type')
.exec(function (err, result) {
if (err) return res.status(500).send(err);
else res.send(result);
});
}
};
Screenshot of view:
If more information is needed please let me know. I thought that something may be wrong with my .populate, but after reading this documentation I think everything is good. I'm stumped.
http://mongoosejs.com/docs/populate.html
I have this mongoose schema
var ContactSchema = module.exports = new mongoose.Schema({
name: {
type: String,
required: true
},
phone: {
type: Number,
required: true,
},
messages: [
{
title: {type: String, required: true},
msg: {type: String, required: true}
}],
address:{ city:String,
state:String
}
});
I have initially the collection set with name and phone field. I need to update the collection with new messages into messages array and new address into address object. the function must also need to handle any single operation, ie in some case i have only update to messages array or updates to both name and address. so how i can i do all operations in a single function.
var messages= {
title: req.body.title,
msg: req.body.msg
}
Model.findOneAndUpdate({'_id': req.body.id,},{$push: {messages:message}},{upsert: true}, function (err, data) {
if (err) {
return res.status(500).send(err);
}
if (!data) {
return res.status(404).end();
}
return res.status(200).send(data);
});
You could try use both the $set and $push operators in your update object. Suppose, for example, you want to update both name and address fields in one single operation, use the $set on the name field and a $push operation to the address array:
var messages= {
title: req.body.title,
msg: req.body.msg
},
query = {'_id': req.body.id},
update = {
$set: {name: req.body.name},
$push: {messages: message}
},
options = {upsert: true};
Model.findOneAndUpdate(query, update, options, function (err, data) {
if (err) {
return res.status(500).send(err);
}
if (!data) {
return res.status(404).end();
}
return res.status(200).send(data);
});