mongoose pull specific data from single document - javascript

So Im using mongoose and mongo atlas. I have a single document with a structure as follows:
{_id: ObjectId("3u3ui4t432) ,
name: cat1,
items :
[
{cat1_item1: "something"},
{cat1_item2: "something"}
]}
{_id: ObjectId("3u3uir3bi2) ,
name: cat2,
items :
[
{cat2_item1: "something"},
{cat2_item2: "something"}
]}
currently this endpoint retrieves the entire document, i am just trying to access one category at a time based of a param either url or body
//this gets the specific document i want, but i would prefer to get that document through something like this.
// findOne({ category: req.body.category })
app.post('/targetCategory', async (req, res) => {
const categoryName = req.body.category
categoryCollection.findOne({ _id: "62b9353730ac42a7d390f5ad" }, (err,
data) => {
if (err) {
console.log(err)
} else {
res.send(data)
console.log(categoryName)
}
})
})
const mongoose = require('mongoose')
const Schema = mongoose.Schema;
const categorySchema = Schema({
categories: {
}
})
module.exports = mongoose.model('categoryCollection', categorySchema)
basically I want to use params(?) to only access one category at a time to minimise data sent to the frontend. How do i go about using something like findOne() with the param being either category1 or category2 as I only want the array inside. I am using mongoose, node and express.

model
const mongoose = require('mongoose')
const Schema = mongoose.Schema;
const categorySchema = Schema({
name: String,
// items placeholder, modify if required
items: String[]
})
const Category = mongoose.model('Category', categorySchema)
module.exports = Category
the controller you can use
app.post('/listOne', async (req, res) => {
try {
const categoryData = await Category.findOne({name: req.body.category})
res.send({category: categoryData})
}
catch (e) {
console.log(e)
}
})
another controller solution I suggest
app.get('/category/:name', async (req, res) => {
try {
const categoryData = await Category.findOne({name: req.params.name})
res.send({category: categoryData})
}
catch (e) {
console.log(e)
}
})

To find single data in collection you can use this function or read this in mongoose docs https://mongoosejs.com/docs/api.html#model_Model.findOne
// Find one adventure whose `country` is 'Croatia', otherwise `null`
await Adventure.findOne({ country: 'Croatia' }).exec();
// using callback
Adventure.findOne({ country: 'Croatia' }, function (err, adventure) {});
// select only the adventures name and length
await Adventure.findOne({ country: 'Croatia' }, 'name length').exec();
and to get parameter in express you can use this
app.get('/users/:userId/books/:bookId', (req, res) => {
res.send(req.params)
})

Related

How I can remove only one object in mongodb, not all objects matching the filter query?

This is my code for deleting object containg name as 'bob':
app.delete('/user/:id', async (req, res) => {
const id = req.params.id;
const query = { name: "bob" }
const result = await userCollection.deleteOne(query);
res.send(result);
});
This code delete all objects that have name as 'bob', but I want to delete any one instance only from db matching this query, not all objects. And is there any way to set count that how many instance I want to delete matching this query?
You can use this code
const ObjectId = require("mongodb").ObjectId;
app.delete('/user/:id', async (req, res) => {
const id = req.params.id;
const query = { _id: ObjectId(id) };
const result = await userCollection.deleteOne(query);
res.send(result);
});

How to add mongoose transaction and create a document?

I want to add a mongoose transaction in the POST method. When creating the transaction it should be creating a document called stock. Can anybody help me figure out what should I do here? I have a node/express/mongoose app with the following:
GoodsRecivedNote controller
router.post('/', async (req, res) => {
const session = await mongoose.startSession()
try {
const _id = await getNextSequence('goodsReceivedNote')
req.body.id = _id
const goodsReceivedNote = new GoodsReceivedNote(req.body)
const stocks = new Stock(req.body)
await goodsReceivedNote.save()
//use mongoose transaction
//creates a loop(data get from the arry called cart in goodsrecivednote)
for (const item of data) {
//insert stock modal(orderNo, packingId, orderSize, poNumber)
item.create({})
//insert(data, {session})
}
await session.commitTransaction()
res.sendStatus(200)
} catch (error) {
await session.abortTransaction()
return res.sendStatus(500)
} finally {
session.endSession()
}
})
GoodsRecivedNote model
const goodsReceivedNoteSchema = new Schema(
{
id: Number,
poNumber: String,
orderedDate: String,
supplier: String,
orderNo: String,
cart: [
{
packingId: Number,
actualSize: String,
orderSize: String,
brandId: Number,
artWork: String,
receivedQty: Number,
grnDate: String,
},
],
},
)
module.exports = mongoose.model(
'GoodsReceivedNote',
goodsReceivedNoteSchema
)
Stock model
const stockSchema = new Schema(
{
id: Number,
poNumber: Number,
orderNo: String,
packingId: Number,
orderSize: String,
receivedQty: Number,
availableQty: Number,
},
)
module.exports = mongoose.model(
'Stock',
stockSchema
)
Maybe you can try something like this
const session = await mongoose.startSession()
session.startTransaction()
const opts = { session }
const stocks = await new Stock(req.body).save(opts)
await goodsReceivedNote.save(opts)
...the rest of your code
When ever you call Save Update or Delete please add opts as option
Answer by 21bn gets the work done but withTransaction() is way better than startTransaction().
I recommend you use withTransaction instead.
const session = await mongoose.startSession();
await session.withTransaction(async (session) => {
// For create..
collection.create({something:"something"},{session:session});
});
For insertmany, updatemany, the rule is basically the same..
collection.updateMany({find_something:"something"},{name:"Some name"},{session:session});
If you want to find a document using session..
collection.findOne({_id: "some_id"}).session(session));

How can I loop through this array inside this instance of my mongoose model?

const postSchema = new mongoose.Schema({
post:[
{postId: String},
{commentComponent: [
{comment: [String]},
]}
]
})
const Posts = mongoose.model('Posts', postSchema)
This is the definition of the schema for modeling the mongodb
const postLinks = await getPostLinks();
const posts = new Posts({
for (let i = 0; i < postLinks.length; i++) {
const comment = await getComment(postLinks[i]) // here it takes postLinks as a paramaeter to get an array of comment
post: [
{postId: postLinks[i]},
{commentComponent: [
{comment: comment}
]}
]
}
})
const result = await posts.save()
is there a way of iterating inside this instance because the for loop here is not working
You need to pass an object to the Posts constructor with a property called post (which probably should be called posts, but will keep the original name below), and for this property, you need to specify an array.
This array can be built by using Array.prototype.map and Promise.all:
const post = await Promise.all(
postLinks.map(async (postLink) => {
const comment = await getComment(postLink);
return {
postId: postLink,
commentComponent: [{ comment }],
};
})
);
const posts = new Posts({ post });
const result = await posts.save();
But if you prefer, you can use the traditional for-loop (more similar to what you were trying to do) as well:
const post = [];
for (let i = 0; i < postLinks.length; i++) {
const comment = await getComment(postLinks[i]);
post.push({
postId: postLinks[i]},
commentComponent: [{ comment }]
});
}
const posts = new Posts({ post });
const result = await posts.save();
Based on your code example I am not certain what you are attempting to do. When using a Model and trying to create you can think of as a new singular record. If you are trying to insert many links into a single record I would suggest comma separating them then inserting that into your MongoDB.
But you cannot iterate inside your Posts class like that.
If I were you I would set up my file something like this:
file: models/Post.js:
const mongoose = require('mongoose');
const PostSchema = new mongoose.Schema({
text: {
type: String,
trim: true,
required: [true, 'Please add some text']
},
link: {
type: String,
required: [true, 'Please add link']
},
createdAt: {
type: Date,
default: Date.now
}
});
module.exports = mongoose.model('Post', PostSchema);
Then create a controller js file
file: controllers/posts.js:
const Post = require('../models/Post');
// #desc Add Post
// #route POST /api/v1/posts
// #access Public
exports.addPost = async (req, res, next) => {
try {
// get post data from the request
// mongo returns a promise so await on it
const post = await Post.create(req.body);
return res.status(201).json({
success: true,
data: post
});
} catch (err) {
if(err.name === 'ValidationError') {
const messages = Object.values(err.errors).map(val => val.message);
return res.status(400).json({
success: false,
error: messages
});
} else {
return res.status(500).json({
success: false,
error: 'Server Error'
});
}
}
}
then in your router file, you can use your controller:
routes/post.js
const express = require('express');
const router = express.Router();
const { addPost } = require('../controllers/posts');
router
.route('/')
.post(addPost);
module.exports = router;

I am New to nodejs and trying to update a category in categories table but it is not working

> I am trying to update a data using updateOne method but i am not able to debug it why it is not working ?
router.post('/edit-category/:slug', async (req,res) =>{
// res.send(req.body.id);
try{
const updatedPost = await Category.updateOne(
{ _id: req.body.id},
{
$set: { title: req.body.title },
$set: { slug: req.body.slug }
}
);
// updatedPost.update((error) => {if(error){console.log("hiiiiiiiii"+error)}});
res.send(updatedPost);
// console.log(updatedPost);
}catch(error){
console.log({message:error})
}
});
Two possibilities:
Check in DB whether the document is there in DB with req.body.id as _id
Try for the below code:
const ObjectId = require('mongodb').ObjectID;
const updatedPost = await Category.updateOne({ _id: ObjectId (req.body.id)}

Why is this mongoose 'findOne' query always returning null?

I am trying to find a specific document with mongoose in my Cosmosdb with this query described below.
const mongoose = require('mongoose');
var ObjectID = require('mongodb').ObjectID
const keys = require('../config/keys');
const Item = mongoose.model('items');
const uploadToBlob = async (containerName, blobName, json, id) => {
console.log('id', id)
Item.findOne({ _id: id }, (foundItem) => {
console.log(foundItem)
});
console.log('here')
Item.findOneAndDelete({ name: blobName });
};
I am successfully able to find the document when querying like this below.
const scanMongo = () => {
Item.find({
_id: {
$gt: ObjectID.createFromTime(Date.now() / keys.mongoPurgeInterval)
}}, (err, foundItems) => {
if(err) {
console.log("Oops", err);
return;
}
foundItems.forEach(item => {
JSON.stringify(item)
const blobName = item.name;
json = "'"+item+"'"
const id = item._id
uploadToBlob(keys.containerName, blobName, json, id);
});
});
}
This is what the object I'm looking for looks like when pulled from the query above.
[ { _id: 5cabd5c6e16288230cba2cf6, name: 'test', value: 1, __v: 0 } ]
For kicks, here my model.
const mongoose = require('mongoose');
const { Schema } = mongoose;
const itemSchema = new Schema({
name: String,
value: Number,
});
mongoose.model('items', itemSchema);
I'm befuddled. Any help would be bawler. Thanks!!!
Yeah, the first parameter is supposed to catch the error.
Item.findOne({ _id: id }, (error, foundItem) => {
console.log(foundItem)

Categories

Resources