USER SCHEMA:
{
friends: [{
user_id: {type: mongoose.Schema.Types.ObjectId, required: true, ref: 'User'},
name: {type: String, required :true},
age: {type: Number, required: true}
}],
privacy_settings : {
visibility : {type : Number, enum: [0,1,2]},
permission : {type : Number, enum : [0,1]},
}
}
Above is a sub section of user schema. I want to filter out the friends whose user id's don't exist. Right now what I get is:
QUERY RESULT:
friends:
[ {},
{},
{},
{},
{},
{ user_id: 570f733f0e3fbfb7690b2384 },
{},
{},
{ user_id: 570f52b30e3fbfb7690b09f4 },
{},
{},
{},
{ user_id: 570f57490e3fbfb7690b0afe },
{ user_id: 571072576952b11f0320f324 } ],
The problem is I don't want these {}, just the data where user_id exists.
QUERY USED
user.findOne(
{_id: some_mongoose_id},
{'friends.userid privacy_settings'}, function(err,result){
console.log(err,result);
}
)
How can I go about this ?
Try This:
user.find({"friends.user_id" : {$ne : null}},function(err,data){
if(data){
//console.log(data);
}
});
Related
I have 2 Collections one for users and other for posts(Posts colllection have _id of users as postedBy).
In users collection each user is having friends array which have _id of users in it.I want to get all the Posts of My friends and mine post in sorted order(sorted By CreatedAt).
This is my Userschema in which i am having friends array of mongoose object type ref to user collection,
here i'm storing users id who is friend.
`//UserSchema
const userSchema = new Schema({
profileImg : {
type: String,
},
name: {
type: String,
required: [true, 'Please Enter Your Name!']
},
about: {
type: String,
},
email: {
type: String,
required: [true, 'Please Enter Email!'],
unique: [true, 'Already Registered!'],
match: [/\S+#\S+\.\S+/, 'is invalid!']
},
password: {
type: String,
required: [true, 'Please Enter Your Password!'],
},
friends: [{
type: mongoose.Types.ObjectId,
ref: 'USER'
}],
address: {
line1: {
type: String,
required: [true, 'Please Enter Your Address!']
},
line2: {
type: String
},
city: {
type: String,
required: [true, 'Please Enter Your City!']
},
state: {
type: String,
required: [true, 'Please Enter Your State!']
},
}
}, { timestamps: true })
This is my Post Schema where userId is ref to users collection and here the _id of user who is uploading post is saved.
//POST SCHEMA
const postSchema = new Schema({
userId: {
type: mongoose.Schema.Types.ObjectId,
ref: "USER",
required: true
},
postImage: {
type: String,
required: [true, 'Please Upload the Image!']
},
caption: {
type: String
},
likes: [likeSchema],
comments: [commentSchema]
}, { timestamps: true })
`
What I am Doing:
1st I am finding the user through _id
2nd from found user's friend array ,lookup in posts collection to get post of friends
3rd Now to get owns post again look up in post collection with own _id
4th concat the both array obtain from friend post and user post as Posts
Now here after step 4 i want to sort the Posts by createdAt but its not working..
How to sort it?
const posts = await User.aggregate([
{
$match: {
_id: mongoose.Types.ObjectId(req.user_id)
}
},
{
$lookup: {
from: "posts",
localField: "friends",
foreignField: "userId",
as: "friendposts"
}
},
{
$lookup: {
from: "posts",
localField: "_id",
foreignField: "userId",
as: "userposts"
}
},
{
$project: {
"Posts": {
$concatArrays: ["$friendposts", "$userposts"]
},
_id: 0
}
}
])
you can use 1 lookup instead of 2 .
for sorting you have 3 ways
sort in the code level (using sort function)
use $unwind $sort and group (if mongo db version is less than 5.2)
use $sortArray (applicable for mongodb version 5.2+)
if using 2nd method.
User.aggregate([
{
'$match': {
'_id': mongoose.Types.ObjectId(req.user_id)
}
}, {
'$addFields': {
'users': {
'$concatArrays': [
'$friends', [
mongoose.Types.ObjectId(req.user_id)
]
]
}
}
}, {
'$lookup': {
'from': 'posts',
'localField': 'users',
'foreignField': 'userId',
'as': 'posts'
}
}, {
'$unwind': {
'path': '$posts'
}
}, {
'$sort': {
'posts.createdAt': -1
}
}, {
'$group': {
'_id': '$_id',
'posts': {
'$push': '$posts'
},
'name': {
'$first': '$name'
}
}
}
])
you can add any other field needed in final response like wise i added name .
I have a Schema of Project that looks like this:
const ProjectSchema = new mongoose.Schema({
name: {
type: String,
Required: true,
trim: true
},
description: {
type: String,
},
devices: [{
name: {type: String, Required: true},
number: {type: String, trim: true},
deck: {type: String},
room: {type: String},
frame: {type: String}
}],
cables: {
type: Array
},
user: {
type: mongoose.Schema.Types.ObjectId,
ref: 'User'
},
adminsID: {
type: Array
},
createdAt: {
type: Date,
default: Date.now
}
I want to query an object from array of "devices".
I was able to add, delete and display all sub-documents from this array but I found it really difficult to get single object that matches _id criteria in the array.
The closest I got is this (I'm requesting: '/:id/:deviceID/edit' where ":id" is Project ObjectId.
let device = await Project.find("devices._id": req.params.deviceID).lean()
console.log(device)
which provides me with below info:
[
{
_id: 6009cfb3728ec23034187d3b,
cables: [],
adminsID: [],
name: 'Test project',
description: 'Test project description',
user: 5fff69af08fc5e47a0ce7944,
devices: [ [Object], [Object] ],
createdAt: 2021-01-21T19:02:11.352Z,
__v: 0
}
]
I know this might be really trivial problem, but I have tested for different solutions and nothing seemed to work with me. Thanks for understanding
This is how you can filter only single object from the devices array:
Project.find({"devices._id":req.params.deviceID },{ name:1, devices: { $elemMatch:{ _id:req.params.deviceID } }})
You can use $elemMatch into projection or query stage into find, whatever you want it works:
db.collection.find({
"id": 1,
"devices": { "$elemMatch": { "id": 1 } }
},{
"devices.$": 1
})
or
db.collection.find({
"id": 1
},
{
"devices": { "$elemMatch": { "id": 1 } }
})
Examples here and here
Using mongoose is the same query.
yourModel.findOne({
"id": req.params.id
},
{
"devices": { "$elemMatch": { "id": req.params.deviceID } }
}).then(result => {
console.log("result = ",result.name)
}).catch(e => {
// error
})
You'll need to use aggregate if you wish to get the device alone. This will return an array
Project.aggregate([
{ "$unwind": "$devices" },
{ "$match": { "devices._id": req.params.deviceID } },
{
"$project": {
name: "$devices.name",
// Other fields
}
}
])
You either await this or use .then() at the end.
Or you could use findOne() which will give you the Project + devices with only a single element
Or find, which will give you an array of object with the _id of the project and a single element in devices
Project.findOne({"devices._id": req.params.deviceID}, 'devices.$'})
.then(project => {
console.log(project.devices[0])
})
For now I worked it around with:
let project = await Project.findById(req.params.id).lean()
let device = project.devices.find( _id => req.params.deviceID)
It provides me with what I wanted but I as you can see I request whole project. Hopefuly it won't give me any long lasting troubles in the future.
I'm trying to query a MongoDB database via mongoose to updateMany the fields of my database. I suppose that the first request is correct because mongoose doesn't fire any error, but for the nested schemas, I'm getting the following error.
My goal is to delete the occurences of the userTag in friends and remove the friendRequestsSent when userTarget equals userTag, friendRequestsReceived when userRequest equals userTag and notification when data equals userTag.
Here are the schemas of my Model
const NotificationSchema = new Schema({
title: String,
type: Number,
icon: String,
data: String,
createdAt: { type: Date, default: Date.now },
})
const FriendRequestSchema = new Schema({
userRequest: { type: String, required: true },
userTarget: { type: String, required: true },
createdAt: { type: Date, default: Date.now },
})
const UserSchema = new Schema({
tag: { type: String, required: true, unique: true },
friendRequestsSent: { type: [FriendRequestSchema] },
friendRequestsReceived: { type: [FriendRequestSchema] },
friends: { type: [String] },
notifications: { type: [NotificationSchema] },
})
The request
const updateResponse = await User.updateMany(
{
friends: { $elemMatch: { $eq: userTag } },
friendRequestsSent: {
userTarget: {
$elemMatch: { $eq: userTag },
},
},
friendRequestsReceived: {
userRequest: {
$elemMatch: { $eq: userTag },
},
},
notifications: {
data: {
$elemMatch: { $eq: userTag },
},
},
},
{
$pull: {
friends: userTag,
friendRequestsSent: { userTarget: userTag },
friendRequestsReceived: { userRequest: userTag },
notifications: { data: userTag },
},
}
)
The error
Error while deleting the user account: Cast to String failed for value "{ '$elemMatch': { '$eq': '0eQzaAwpt' } }" at path "userRequest" for model "User"
The userRequest field in friendRequestsReceived is type String, not array so $elemMatch will not work. Also, you don't need to use $elemMatch because you specify only a single condition in the $elemMatch expression as it says in the docs:
If you specify only a single condition in the $elemMatch expression, you do not need to use $elemMatch.
In your case, you just need to do something like (details here):
await User.updateMany({
friends: userTag,
"friendRequestsSent.userTarget" : userTag,
"friendRequestsReceived.userRequest": userTag,
"notifications.data": userTag
}...
I am trying to delete one array element when I click delete button on jade view page.
When clicked, it's going to send selected instructor objected as req.body.
At sever side, it will find courses that contain the instructor objectId.
Any idea for me?
Thank you for reading it.
here is my code:
var id = req.body._id;
clist.find({ instructors: { $in: [id] } }).exec(function (err, result) {
result.forEach(function (obj) {
clist.update(
{ _id: new mongoose.Types.ObjectId(obj._id)},
{ $pull: { instructors : [new mongoose.Types.ObjectId(id)] } }
);
console.log(new mongoose.Types.ObjectId(obj._id) + ' was deleted');
});
});
Schema Clist and ilist:
var instructorlist = mongoose.Schema({
name: { type: String, required: true },
age: { type: Number, required: true },
gender: { type: String, required: true },
DOB: { type: Date, required: true, default: Date.now },
email: { type: String, required: true },
phone: { type: Number, required: true },
address: { type: String, required: true },
dateofstart: { type: Date, required: true},
courses: [{
type: mongoose.Schema.Types.ObjectId,
ref: "clist"
}]
});
var courselist = mongoose.Schema({
coursename: { type: String, required: true },
coursenumber: { type: String, required: true },
coursecredit: { type: Number, required: true },
courseroom: { type: String, required: false },
courseregisteddate: {type: Date, default: Date.now},
students: [{
type: mongoose.Schema.Types.ObjectId,
ref: "slist"
}],
instructors: [{
type: mongoose.Schema.Types.ObjectId,
ref: "ilist"
}]
});
one example for mongodb :
{
"_id": {
"$oid": "591a7a3b391a1842e8a69e23"
},
"coursename": "JDKD",
"coursenumber": "COMP4483",
"coursecredit": 4,
"courseroom": "sdaf",
"instructors": [
{
"$oid": "591a374422a3a13d38c0bbe5"
}
],
"students": [],
"courseregisteddate": {
"$date": "2017-05-16T04:04:11.848Z"
},
"__v": 0
}
When I add instructor objectID in Course.
var newcourse = new clist({
'coursename': req.body.coursename, 'coursenumber': req.body.coursenumber, 'coursecredit': req.body.coursecredit
, 'courseroom': req.body.room, 'instructors': instructors._id
});
Use same operation to find and update multiple
clist.update(
{ instructors: { $in: [id] }},
{ $pull: { instructors : { _id : new mongoose.Types.ObjectId(id) } } }, //or{ $pull: { instructors: mongoose.Types.ObjectId(id) } }
{
multi:true
},
function(error, success){
if(error){
console.log("error",error)
}
console.log("success",success)
});
I'm trying to order the next model by ts (timestamp):
var Schema = new mongoose.Schema({
info: {
name: { type: String, trim: true, validate: [
{ validator: validations.user.maxName, msg: 'The name must be shorter' }
]}
},
gender: { type: String, trim: true, enum: ['Male', 'Female'] },
notifications: [{
story: {
_id: { type: mongoose.Schema.Types.ObjectId, ref: 'Story' },
video_id: { type: mongoose.Schema.Types.ObjectId, ref: 'Video' }
},
video: {
_id: { type: mongoose.Schema.Types.ObjectId, ref: 'Video' },
video_id: { type: mongoose.Schema.Types.ObjectId, ref: 'Video' }
},
type: { type: String },
read: { type: Number, default: 0 }, // 0 - Unread, 1 - read
ts: { type: Date, default: Date.now }
}]
}, { timestamps: { createdAt: 'created_at' } });
This is the code I'm trying to use in order to order these notification elements is what it follows:
UserSchema.statics.getNotifications = function (user_id) {
return this.findById(user_id)
.select('notifications')
.populate({
path: 'notifications.story.video_id',
select: '_id user story',
populate: ([{
path: 'user',
select: '_id nickname info.thumbnail'
}, {
path: 'story',
select: 'title'
}])
})
.populate({
path: 'notifications.video.video_id',
select: '_id user story parent',
populate: ([{
path: 'user',
select: '_id nickname'
}, {
path: 'story',
select: '_id'
}])
})
.sort({ 'notifications.ts': -1 })
.exec();
};
But instead of sorting my notifications, I guess I'm sorting the users that return my query with all the notifications.
Is there any way to sort for a given user, the notifications?
Inside your populate you want to sort you can
.populate({ path: 'theoneyouwanttosort', options: { sort: { createdAt: -1 } } })
Hope that can help you :)
Thanks to #JohnnyHK here bellow I leave the answer of my question:
Schema.findByIdAndUpdate(user_id, {
$push: {
notifications: {
"$each": [{
story: {
parent: mongoose.Types.ObjectId(video_bookmarked),
video_id: mongoose.Types.ObjectId(video_id),
},
type: 'respond-video'
}],
"$sort": { ts: -1 }
}
},
$inc: { count_notifications: 1 }
}).exec();