how to get the existing collection in mongodb using mongose- Nodejs - node.js

In my mongodb i already had a collection and document
Now, i want to use this collection in my node-js using mongoose. how we do this.
const mongoose = require("mongoose");
const schema = mongoose.Schema;
const adminLogin = new schema({
name: { type: String, required: true },
password: { type: String, required: true }
})
module.exports = mongoose.model("adminDetails", adminLogin)
while doing this it is creating new collection. Unable to use the existing collection.

At first you need to make a GET method Router in your jsFile.
like this
app.get("/mainData", async (req, res) => {
const menuInfo = await Nutrients.find({});
res.json(menuInfo);
});
You can set and use VSCode extension "thunderClient"!
like this
enter image description here
setting your request method and URI endpoint
(when you user GET method to get some data in your case, you don't need to write something in request body)
Then, you can see your data on the 'response part' as an Object Data.
If you want to use your data on Front side on your Project, you can use like this!
(in my case, I used jQuery. )
function menu_show() {
$('#result_list').empty()
$.ajax({
type: 'GET',
url: '/mainData', //you need to write same url with your no3.
data: {},
success: function (response) {
console.log(response)
let rows = response['menus']
for (let i = 0; i < rows.length; i++) {
let menuName = rows[i]['menuName']
console.log(menuName)
}
}
}
This is my answer. Let me know if you've solved it!

the image 1 is the structure in the MongoDB. I want to read the data from that collection, below is the code using and the URL and output in post man.
route.get('/adminLogin', (request, response) => {
const data = adminDetails.find({}, (err, result) => {
if (err) {
console.log(err)
} else {
res.json(result)
}
})
})
http://localhost:5000/admin/adminLogin

Related

MongoDb bulkWrite is not working for me in node.js

This is my first time of using bulkWrite to carry out updates via mongoose. I am building a blog application and I am using it to learn MERN stack. I have a Post model. The Post model has object value which is an array. This is an example of it:
const PostSchema = new mongoose.Schema(
{
postLikes:{
type: Array,
default: []
}
}
)
The postLikes contain mongodb object ids of users who liked a post.
I have a logic for deleting selected users or all users by an admin. The like system does not come with a Like Model of it own. I simply used an array system inside the post model. After deleting a user, I would like to update all post models with likes of the selected users. Some users may have multiple likes across different posts.
In my node, I created a variable like this:
const {selectedIds} = req.body;
The selectedIds came from reactjs like this:
const [selectedUsers, setSelectedUsers] = useState([]);
const arrayOfSelectedUserId = (userId) =>{
setSelectedUsers(prevArray => [...prevArray, userId]);
);
}
For the request, I did it like this:
const response = await axiosPrivate.post(`/v1/users/deleteSelected`, selectedIds, { withCredentials: true,
headers:{authorization: `Bearer ${auth.token}`}})
In nodejs, the selectedUsers ids was passed to this variable:
const {selectedIds} = req.body;
I created the logic this way:
const findIntersection = (array1, array2) => {
return array1.filter((elem) => {
return array2.indexOf(elem) !== -1;
});
}
const filteredPost = posts.filter((singleFilter) => {
const intersection = findIntersection(selectedIds, singleFilter.postLikes);
return singleFilter.postLikes.length !== 0 && intersection.length !== 0;
});
const updatedPosts = filteredPost.map((obj)=>{
const intersection = findIntersection(selectedIds, obj.postLikes);
console.log(intersection )
return {
updateOne: {
filter: { _id: obj._id },
update: { $pull: { postLikes: { $in: intersection } } },
},
};
});
Post.bulkWrite(updatedPosts).then((res) => {
console.log("Documents Updated", res.modifiedCount)
})
The console.log shows the text Document updated and showed number of documents updated. However, if I check my database, the update won't reflect. This means that the selected users' ID is still in the array.
Is there a better method? What Am I doing wrong?

NodeJs: how to assign additional objects to mongoose query response JSON

Using mongoose I am querying a list of posts and would like to determine whether or not the user has liked the image or not within the query function by adding a boolean to the response JSON. I am trying to do this in a for loop.
However, when I console.log(), the post with the field returns correctly but does not amend it to the JSON.
My function:
function(req, res) {
var isLiked, likeCount;
Post
.find(/* Params */)
.then(posts => {
for (var index in posts) {
posts[index].isLiked = posts[index].likes.includes(req.headers.userid)
console.log(posts[index]) // does not show 'isLiked' field in JSON
console.log(posts[index].isLiked) // response is correct
}
res.send(posts) // does not have 'isLiked field
})
},
Post schema:
var postSchema = new Schema({
userId: {
type: String,
required: true
},
caption: {
type: String,
required: false
},
likes: [{
type: String,
}]
});
To add properties to queries objects you should convert them to JS objects:
function getPosts(req, res) {
Post.find(/* Params */).then((posts) => {
const result = [];
for (const post of posts) {
const postObj = post.toObject();
postObj.isLiked = postObj.likes.includes(req.headers.userid);
result.push(postObj)
}
res.send(result);
});
}
Cuz
Post.find()
is not return an object, you can set prop isLiked to posts[index] but it's private.
Easy way to fix it is use lean() method to get return object
Post.find().lean()
.then(//do what you want)

How Should I Store Data In SubSchemas in MongoDB and Node JS?

In MongoDB, you store data by writing a schema and you use to do all your operation through some routing. My question is how should I store user data. Something like this:
const Page = new mongoose.Schema({
username: String
Password: String
lists: [{
list_name: String,
etc.
}]
});
This is the way that I want to do it because no one else would be able to access anyone else's Lists. My Issue is let's say they update a certain list_name how would I update ONLY that certain list_name instead of updating everything. Im sort of new to MongoDB so any help would be appreciated.
do thaun helped me out by linking me to the docs. After looking at the docs I found a bunch of things that I was not using. With that being said here is the Schama that I ended up using.
const Task = new mongoose.Schema({
text: {type: String, required: true}
})
const Page = new mongoose.Schema({
list_name : {type: String, unique: true},
task: [Task]
});
For accessing the Task schema for a post I did this.
router.post('/lists/:list', async (req, res) => {
try {
console.log(await Question.findOne({_id: req.params.list}))
const question = await Question.findOneAndUpdate({"_id": req.params.list}, {"$push": {task:{"text": req.body.text}}}, {new:true})
if (!question)
return res.status(404).json({})
else
return res.status(200).json(question)
} catch (error) {
return res.status(500).json({"error":error})
}
})
The get was a little bit more tricky because I couldn't find use findOne so I used a for loop. here is the code for the get.
router.get('/lists/:list/:task', async (req, res) => {
try {
const _list = req.params.list
const _task = req.params.task
console.log(_task)
const question = await Question.findOne({_id: _list})
for (let index = 0; index < question.task.length; index++) {
if(req.params.task = question.task[index]._id)
return res.status(200).json(question.task[index])
}
return res.status(404).json({})
} catch (error) {
return res.status(500).json({"error":error})
}
})
I hope this helps someone because it was a bit annoying to get this information. Cheers!

mongoose filter by multiple conditions and execute to update data

I am wondering what would be the best approach to make schema functions using mongoose. I have never used this so the way I think is somewhat limited, same goes for looking for docs, without knowing what's available, is not very efficient.
Through docs I found that either using findOneAndUpdate might solve the problem; but there are some constraints.
Here is the code I am planning to run:
models/Bookmark.js
const mongoose = require('mongoose')
const bookmarkItemSchema = new mongoose.Schema({
restaurantId: String,
cachedAttr: {
name: String,
latitude: Number,
longitude: Number,
},
})
const bookmarkListSchema = new mongoose.Schema({
listName: String,
items: [bookmarkItemSchema],
})
const bookmarkSchema = new mongoose.Schema({
userId: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User',
},
lists: [bookmarkListSchema],
})
// const add = (lists, userId) => {
// let bookmark = Bookmark.findOne({userId})
// bookmark.lists.listName === lists.listName //current, new
// ? bookmark.lists.items.push(lists.items)
// : bookmark.lists.push(lists)
// return bookmark
// }
mongoose.model('Bookmark', bookmarkSchema)
Routes/bookmark.js
router.post('/bookmarks', async (req, res) => {
const {lists} = req.body
console.log(lists)
if (!lists) {
return res.status(422).send({error: 'You must provide lists'})
}
let bookmark = Bookmark.findOne({"userId": req.user._id})
if (bookmark.lists.listName === lists.listName){
let item = lists.items
bookmark.lists.items.push(item)
await bookmark.save()
res.send(bookmark)
}
try {
// const bookmark = Bookmark.add(lists, req.user._id, obj)
// await bookmark.save()
// res.send(bookmark)
let bookmark = Bookmark.findOne({"userId": req.user._id})
if (bookmark.lists.listName === lists.listName){ // THIS IS UNDEFINED. How to get this object?
let item = lists.items
bookmark.lists.items.push(item)
await bookmark.save()
res.send(bookmark)
}
} catch (e) {
res.status(422).send({error: e.message})
}
})
The req.body looks like this:
{
"lists": {
"listName": "My Saved List",
"items": {
"restaurantId": "abcdefg",
"cachedAttr": {
"name": "abcdefg",
"latitude": 200,
"longitude": 200
}
}
}
}
Basically what I commented out in the models/Bookmark.js file is what I would really like to do.
If the userId's list name already exists, then I would like to just add an item to the list.
Otherwise, I would like to add a new list to the object.
What is the best approach for doing this? Is there a straight forward mongoose api that I could use for this problem? or do I need to make two separated function that would handle each case and make that as schema methods and handle it in the routes file?

How to save the result in variable of findOne() Mongoose using nodejs

I am trying to save the result of findOne(), however, I do not have any idea how to save this result in a variable.
function createSubscription (req, res, next) {
let product_id = "P-5JM98005MT260873LLT44E2Y" ;
let doc = null;
product.findOne({"plans.id": product_id}, { "plans.$": 1
}).sort({create_time: -1}).exec(function(err, docs) {
if(err) {
} else {
if(docs != null) {
this.doc = docs;
}
}
});
console.log(doc);
let result = null;
if (doc.create != null) {
result = processDoc(doc);
}
}
function processDoc(doc) {
//do something
return resul;
}
function processResult(result) {
//do something
}
Below, I copy the product schema
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const ProductSchema = new Schema({
id: {
type: String,
trim: true,
required: true,
},
name: {
type: String,
required: true,
},
description: {
type: String,
required: true,
},
create_time: {
type: Date,
required: true,
}
});
module.exports = mongoose.model('Product', ProductSchema);
The doc is always null and does not receive the value.
In general terms, I would like to get the response product.findOne to use another function, calling by createSubscription()
To save the result of findOne() is as easy as this:
var doc = product.findOne();
The problem you're having is that you are calling processDoc() before findOne() is finished. Look into asynchronous javascript. You can fix this by using async/await like this:
async function createSubscription (req, res, next) {
var doc = await product.findOne();
processDoc(doc);
}
The reason is you are calling a callback function, which means function is asynchronous. So there is no guarantee that your query will execute and the values will be set before it reaches to,
if (doc.create != null) {
result = processDoc(doc);
}
To resolve this you may use the Async/Await Syntax:
const createSubscription = async function (params) {
try { return await User.findOne(params)
} catch(err) { console.log(err) }
}
const doc = createSubscription({"plans.id": product_id})
Since you want to query something in database, that means you already created one and saved some data in it.
However before saving data in the database you should be creating your model which should be created under models folder in Product.js(model names should start capital letter in convention) . Then you have to IMPORT it in your above page to access it. You want to query by product.id but which product's id?
Since you have req in your function, that means you are posting something. If you set up the proper settings in app.js you should be able to access to req.body which is the information that being posted by the client side.
app.js //setting for parsing(reading or accessing) req.body
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
Now we can reach req.body.id
this should be your code:
function createSubscription (req, res, next) {
const product=Product.findOne({plan.id:req.body.id})
.
.
}
If you noticed I did not put this plan.id in quotes.Because findOne() method belongs the Product model and that model belongs to the package that you are using. (In mongoose you query without quotes, in mongodb client you query in quotes)
findOne() is an asynchronous operation means result will not come to you immediately. So you should always keep it in try/catch block.
function createSubscription (req, res, next) {
try{
const product=Product.findOne({plan.id:req.body.id})
}
catch(error){console.log(error.message)} //every error object has message property
.
.
}
Lastly since you are querying only one object you do not need to sort it.

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