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Mongo findById() only works sometimes even when passed a valid ID

I am having a strange issue querying a Mongo DB collection. I am using findById() to get a single item that works sometimes and not others.
I have checked the id being passed to the server route and in all cases, they match perfectly with the targeted document in the collection.
Here is the basic code:
router.get("/:postId", async (req, res) => {
console.log('id : ', req.params.postId)
console.log('type: ', typeof(req.params.postId)) // id is a string
try {
const post = await Post.findById(req.params.postId).exec();
console.log('post :', post) // sometimes null
res.json(post);
} catch (err) {
res.json({ message: err });
}
});
In the above route, only certain posts will be found while others come back null. This happens regardless of whether the id passed is correct and the document exists with the exact id.
If anyone has any ideas about what could be going wrong here I'd much appreciate the help!
EDIT
I have done some more debugging and think it is something to do with the Schema for the Post model.
For example, this object will be found:
{
"tags": ["foo"],
"_id": "8394839483fhg020834903",
"title": "bar",
"content": "baz",
"isPrivate": true,
}
But this one will not because of the missing isPrivate property.
{
"tags": [],
"_id": "5e0fdc631ef5c46b285a4734",
"title": "New post",
"content": "Some content here",
}
I have tested this across multiple queries and it appears to the root of the problem.
I have tried adding
isPrivate: {
required: false
}
To the Schema but it doesn't seem to solve the issue.
Here is the full Schema
const postSchema = mongoose.Schema({
title: {
type: String,
required: true
},
content: {
type: String,
required: true
},
tags: [{ type: String }],
date: {
type: Date,
default: Date.now
},
isPrivate: {
type: Boolean
required: false
}
});
I'm not a Mongo/Mongoose expert, so any guidance would be much appreciated.

If post id match with any record it return data, otherwise it will return null. You should handle the exception
router.get("/:postId", async (req, res) => {
try {
const post = await Post.findById(req.params.postId).exec();
if(post) {
return res.json(post);
}
res.json({ message:'No Post found' });
} catch (err) {
res.json({ message: err });
}
});
You can manually check is record exists against a post id. You can use MongoDB Compass for gui browse the record

I believe the issue might be with your _id as per mongo standard _id should be a String is of 12 bytes or a string of 24 hex characters.
We can check if the _id is valid using mongoose.isValidObjectId()
I did run this check on your objects that you posted and indeed 1 is invalid while other is valid
const mongoose = require('mongoose');
console.log(`is '8394839483fhg020834903' valid - ${mongoose.isValidObjectId('8394839483fhg020834903')}`);
console.log(`is '5e0fdc631ef5c46b285a4734' valid - ${mongoose.isValidObjectId('5e0fdc631ef5c46b285a4734')}`);
It gives me
You will have to check what is modifying your ID's in the code, you can upload your schema to get a better understanding as well.

How to post the JSON data in a embed in discord.js

I wrote a code and i got the data in a json format. Now i want it to convert that data into a discord embed so that when i enter a command . EX:- .data the json data to be sent from the URL.
Here is the input
request({
url: "https://data.vatsim.net/v3/vatsim-data.json",
json: true
}, (err, response, body) => {
console.log(body)
})
The json data looks like this :
{
cid: 1435807,
name: ' ',
callsign: 'ZAP85LJ',
flight_plan: [Object],
last_updated: '2021-10-24T10:45:52.516736Z'
},
{
cid: 1439854,
name: ' ',
callsign: 'DLH1ML',
flight_plan: [Object],
last_updated: '2021-10-24T10:46:13.4226778Z'
}

You can use EmbedFields, you can use up to 25 fields on an embed. On this example I used .forEach so that for each element on the array I can create a field with its value:
request({
url: "https://data.vatsim.net/v3/vatsim-data.json",
json: true
}, (err, response, body) => {
const embed = new Discord.MessageEmbed()
const pilots = body.pilots.slice(0, 15)
body.pilots.forEach(pilot => {
embed.addField(p.name,
`CID : ${p.cid}
Server : ${p.server}
etc...`)
})
message.channel.send(embed)
}
If you really want to show every single one of your elements on the array you can use discord-buttons to make the embed edit its message and change pages but for now this is the simplest and easiest solution for you.

Axios sends an array of strings instead of an array of objects

Axios sends an array of strings instead of an array of objects. I have an array of objects that contains data about the event. I'm trying to send a request to the server via axios, but I get a array of strings insteenter image description heread of objects at the output
let data = {
title: 'Game',
subject: 'Some subject',
date: ['01/01/2021','01/01/2021'],
years: ['1970', '1970'],
address: 'None',
ages: [
{
title: 'Men',
weights: [{page: 0, title: '60'}]
}
]
};
api.Create({
params: data
}).then(function (response) {
console.log(response.data);
})
.catch(function (err) {
console.log(err);
});
api response

try to:
console.log(JSON.parse(response.data))
What you get back from the server is string. you need to parse it.
When you send data to and from a server, it is sent as a 'serialized' string, usually JSON format
That's how server responses work

It turned out to be an incorrect request. I used GET to pass the object, instead of POST, so it converts it to a string. I want to notice that there is an evil community on this site.

Mongoose: CastError on querying incorrect ObjectId for nested object

I have following schema
var Topic= new Schema({
text: String,
topicId: String,
comments: [{type: Schema.Types.ObjectId, ref:'Comment'}]
});
var Comment = new Schema({
text: String
});
I am writing RESTFul API that will give me the Comment details as per topic ID and Comment ID
/topics/{id}/comments/{id}
Following is the function that gets data from Mongo
getCommentsById: function(req, resp){
req.db.Topic.findOne({"topicId": req.params.topicId})
.populate({path:"Comments", match:{"_id": req.params.commentId}})
.exec(function(err, topic){
if(err) {
return resp.status(500).json({
message: 'Error when getting Topic.',
error: err
});
}
if (!topic) {
return resp.status(404).json({
message: 'No such Topic'
});
}
if (!topic.comments || topic.comments.length==0) {
return resp.status(404).json({
message: 'No such Comment'
});
}
resp.json(topic.comments[0]);
});
}
The code works fine if I specify the right comment ID, but if I specify non-existing comment ID in URL then I get following error
{
"message": "Error when getting Topic.",
"error": {
"message": "Cast to ObjectId failed for value \"57c738b66d790f0c1bdb179\" at path \"_id\"",
"name": "CastError",
"kind": "ObjectId",
"value": "57c738b66d790f0c1bdb179",
"path": "_id"
}
}
What is the issue here and how to fix it?? Is there better way to query the required object?

The issue isn't that your specifying a non-existing comment ID. It's that you're specifying a string that can't be converted into a valid ObjectId. Your test string, "57c738b66d790f0c1bdb179" is a 23 character hex string. It should be length 24.
If you want to validate before attempting your query, there are several different ways you could go about it. Here's one example: Can I determine if a string is a MongoDB ObjectID?

Dynamic html form generation in MEAN stack

I've just started learning on MEAN stack and need to generate dynamic forms on the fly.
The requirement is to import document (excel/csv/xml/xls etc..) and generate dynamic forms using it so a user can update their data and again export it into the respective file.
So to accomplish this I'm converting documents to JSON format and storing JSON data into the MongoDB database.
Ex: Consider this xlsx data:
ID Name dob Gender
1 user1 7-Dec-87 m
2 user2 8-Dec-87 f
3 user3 9-Dec-87 f
3 user4 4-Dec-87 m
And I'm converting this using xlsx-to-json module to JSON format and storing it into Mongodb.
app.post('/myapp', function (req, res) {
//console.log("===========" + req.file.path);
converter({
input: req.file.path,
output: "output.json"
}, function (err, result) {
if (err) {
console.error(err);
} else {
console.log(result);
db.collection('test').insert(result, function (err, doc) {
console.log(err);
res.json(doc);
});
}
});
});
Here I'm fetching above data from Mongodb & express.js
app.get('/myapp', function (req, res) {
db.collection('test').find(function (err, docs) {
console.log(docs);
res.json(docs);
});
});
app.get('/birthdaylist/:id', function (req, res) {
var id = req.params.id;
console.log(id);
db.collection('test').findOne({_id: mongojs.ObjectId(id)}, function (err, doc) {
console.log(JSON.stringify(doc));
res.json(doc);
});
});
and here's the JSON output:
[
{ dob: '7-Dec-87', ID: '1', Name: 'user1' },
{ dob: '8-Dec-87', ID: '2', Name: 'user2' },
{ dob: '9-Dec-87', ID: '3', Name: 'user3' },
{ dob: '4-Dec-87', ID: '4', Name: 'user4' }
]
So, I've few queries:
Is this the correct approach I'm doing to generate dynamic form from xlsx/csv..etc ? If yes, then how can I generate dynamic form from above JSON.
While exploring on google I've found mongodb generates form automatically (https://github.com/GothAck/forms-mongoose)
So will it help because there may be chance of huge data on excel files.
Any help would be really appreciated.

Do you actually need to analyze an arbitrary spreadsheet and dynamically extract the schema, or do you know the schema ahead of time? If you know the schema, then the Mongoose form generating example is straightforward. But make sure that is actually a requirement because it is tough.
You are never going to be 100% because spreadsheets are created by users and users do weird things. But you can make something that works most of the time.
You need something that takes a JSON object and extracts the schema and puts that in a Mongoose schema format.
So you want to add an interesting module to Mongoose schema. I searched node-modules.com and this came up: https://github.com/Nijikokun/generate-schema

Form generation is not a trivial task. You may want to consider using a library for this. Here are a few that might be useful to you:
http://schemaform.io/
https://github.com/jdorn/json-editor/
Also, if you need help generating JSON schema from JSON:
http://jsonschema.net/#/
and of course: http://json-schema.org/