I have three schemas, that need them to be separated and I can't use subdocuments. The important one is this
export var TestSchema = new mongoose.Schema({
hash: { type: String, index: { unique: true }, default: common.randomHash },
date: { type: Date, default: Date.now },
result: { type: Object },
user: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },
data: { type: Object },
finished: Date,
lang: { type: String, default: 'pt' },
benchmark: { type: String, required: true },
order: { type: mongoose.Schema.Types.ObjectId, ref: 'Transaction' },
/* TODO: remove */
name: { type: String }
});
I have a query that does the populate (it's actually a pagination helper, but I'm cutting to the chase):
TestModel.find({hide: {$ne: true}, user: id}).populate({
path: 'user',
match: {$or: [
{email: new RegExp(search, i)},
{name: new RegExp(search, i)},
{empresa: new RegExp(search, i)},
]}
}).exec().then(/*...*/)
when populate.match doesn't find anything, it sets the user to null. I tried setting the find({'user':{$ne: null}}) but it ignores it. (I guess the populate happen after the find call, maybe that's the reason).
Is there any way I can filter it in the database layer instead having to rely on iterating of the results, check for null then filter out?
This answer on GitHub clarifies that it is not possible with populate, due to how MongoDB works. However, you should be able to do it with $lookup.
Related
I get the following error Cannot create field 'likes' in element whenever I am trying to push into my likeList array nested inside my comments.
When executing the following:
Feed.findOneAndUpdate(
{
owner: req.body.authorId,
"posts.comments.commentList._id": req.body.commentId
},
{
$push: {
"posts.$.comments.commentList.likes.likeList": {
user: req.user._id,
avatar: req.user.profile.profile_picture.url,
name: req.user.name
}
)
And my schema is as follows:
Feed Schema
owner: {
type: Schema.Types.ObjectId,
ref: "userType"
},
posts: [
{
author: {
userType: {
type: String,
enum: ["IndustryPartner", "User", "School"]
},
user: {
type: Schema.Types.ObjectId,
ref: "posts.author.userType", //<- This may cause an issue, if there are any issues with retrieving user fields, CHECK THIS
required: true
},
name: { type: String, required: true },
avatar: { type: String, required: true }
},
comments: {
totalComments: { type: Number, default: 0 },
commentList: [
{
likes: {
totalLikes: { type: Number, default: 0 },
likeList: [ <---//Trying to push here
{
user: { type: Schema.Types.ObjectId, ref: "User" },
avatar: { type: String },
name: { type: String },
date: {
type: Date,
default: Date.now
}
}
]
...
I am not sure if it's an issue with the query I am using in the first parameter to filter.
Update entire error message
It is odd because it appears that it is actually finding the correct commentList to go to, but is unable to access the likes field within the array itself. Am I wrong assuming that this should be able to step through it? posts.$.comments.commentList.likes.likeList
{ MongoError: Cannot create field 'likes' in element {commentList: [ { likes: { totalLikes: 0, likeList: [] },
_id: ObjectId('5cf6b3293b61fe06f48794e3'), user: ObjectId('5c9bf6eb1da18b038ca660b8'), avatar: "https://sli.blob.core.windows.net/stuli/
profile-picture-e1367a7a-41c2-4ab4-9cb5-621d2008260f.jpg", name: "Luke Skywalker", text: "Test comment from Luke", repliesToComment: [], date: new Date(1559671593009) } ]}
After further research, it appears the positional operator is no longer useful after stepping through 2 levels of arrays. So, the solution would be to use JS to change push the values into the array and then save them.
I am using Nodejs and MongoDB, mongoose and expressjs, creating a Blog API having users, articles, likes & comments schema. Below are schemas that I use.
const UsersSchema = new mongoose.Schema({
username: { type: String },
email: { type: String },
date_created: { type: Date },
last_modified: { type: Date }
});
const ArticleSchema = new mongoose.Schema({
id: { type: String, required: true },
text: { type: String, required: true },
posted_by: { type: Schema.Types.ObjectId, ref: 'User', required: true },
images: [{ type: String }],
date_created: { type: Date },
last_modified: { type: Date }
});
const CommentSchema = new mongoose.Schema({
id: { type: String, required: true },
commented_by: { type: Schema.Types.ObjectId, ref: 'User', required: true },
article: { type: Schema.Types.ObjectId, ref: 'Article' },
text: { type: String, required: true },
date_created: { type: Date },
last_modified: { type: Date }
});
What I actually need is when I * get collection of articles * I also want to get the number of comments together for each articles. How do I query mongo?
Since you need to query more than one collection, you can use MongoDB's aggregation.
Here: https://docs.mongodb.com/manual/aggregation/
Example:
Article
.aggregate(
{
$lookup: {
from: '<your comments collection name',
localField: '_id',
foreignField: 'article',
as: 'comments'
}
},
{
$project: {
comments: '$comments.commented_by',
text: 1,
posted_by: 1,
images: 1,
date_created: 1,
last_modified: 1
}
},
{
$project: {
hasCommented: {
$cond: {
if: { $in: [ '$comments', '<user object id>' ] },
then: true,
else: false
}
},
commentsCount: { $size: '$comments' },
text: 1,
posted_by: 1,
images: 1,
date_created: 1,
last_modified: 1
}
}
)
The aggregation got a little big but let me try to explain:
First we need to filter the comments after the $lookup. So we $unwind them, making each article contain just one comment object, so we can filter using $match(that's the filter stage, it works just as the <Model>.find(). After filtering the desired's user comments, we $group everything again, $sum: 1 for each comment, using as the grouper _id, the article's _id. And we get the $first result for $text, $images and etc. Later, we $project everything, but now we add hasCommented with a $cond, simply doing: if the $comments is greater than 0(the user has commented, so this will be true, else, false.
MongoDB's Aggregation framework it's awesome and you can do almost whatever you want with your data using it. But be aware that somethings may cost more than others, always read the reference.
This is my user model:
const UserSchema = new mongoose.Schema(
{
email: { type: String, required: true, unique: true },
watched: [{ type: String}],
watchLater: [{ type: String}],
},
{ timestamps: true },
)
there is watched and watchLater array which contains strings. When I add a string to watched I want to remove or make sure there is no same string on watchLater and vice versa. What's the best approach for this? Do I have to query both keys separately, compare, and write back to the database or there is some other way?
You can put the criteria in query part
db.collection.update(
{ watched: { $ne: string } watchedLater: { $ne:string }},
{ $push: { watched: string }}
)
I have a db in Mongo with users. I want to retrieve all user that are not in my blocked Array. tried to filter through the results by retrieving All documents but I wonder if that's the most efficient way. Is there a way in Mongo to find all users that are not part of an array?
Here is my User model:
var UserSchema = mongoose.Schema({
username: {
type: String,
index:true,
unique: true
},
password: {
type: String
},
email: {
type: String,
unique: true
},
name: {
type: String
},
latitude:{
type: String
},
longitude:{
type: String
},
blocked:{
type: Array
},
friends:{
type: Array
},
photo:{
type: String
},
identity:{
type: String
},
age:{
type: String
},
herefor:{
type: String
},
conns:{
type: Number
},
status:{
type: String
}
}, { collection: 'users' });
You are probably looking for something like the following, assuming your blocked users array contains usernames and your mongoose model is called UserModel:
var blockedUsernamesArray = [];
UserModel.find({ username: { $nin: blockedUsernamesArray } }, function(err, docs) {
// Handle result
})
I have searched for join two collection in MongoDB. I found populate. But it is not working for my scenario. I am using mongoose in node js. My schema are like below.
const CoordinateSchema = new mongoose.Schema({
activationId: {
type: mongoose.Schema.ObjectId,
ref: 'Activation'
},
mac: {
type: mongoose.SchemaTypes.String,
required: true,
set: toLower
},
t: { type: Date },
userId: {
type: mongoose.Schema.ObjectId,
ref: 'User'
}
});
const UserSchema = new mongoose.Schema({
email: {
type: mongoose.SchemaTypes.String,
required: true,
//unique: true,
set: toLower
},
mac: {
type: mongoose.SchemaTypes.String,
required: true,
unique: true,
set: toLower,
index: true
},
dob: {
type: mongoose.SchemaTypes.Date,
},
gender: { type: mongoose.SchemaTypes.String, set: toLower },
activations: [{
activationId: {
type: mongoose.Schema.ObjectId,
ref: 'Activation'
},
userType: { type: mongoose.SchemaTypes.String, set: toLower },
_id: false
}]
}
i have thousands of records for single activation in coordinates collection.
My query query requires to filter distinct mac from coordinates collection which matches userType in user collection.
If i use populate method & then apply filter on that it won't restrict fetching record count because of it query is taking so much time because it will return thousands of records.
I want to fetch only coordinates which match userType in user collection.
So far i haven't found any efficient method to join two collection & apply where condition on it.
I want to know efficient method to join two collection in mongodb & apply where condition on both collections.