Questions tagged [mongodb-lookup]
41 questions
17
votes
1 answer
MongoDB $lookup vs Mongoose populate
I have seen this and other similar titled questions, none answer my question.
I was going through the mongoose documentation where I read
MongoDB has the join-like $lookup aggregation operator in versions >=
3.2. Mongoose has a more powerful…
YulePale
- 6,688
- 16
- 46
- 95
4
votes
1 answer
MongoDB lookup Algorithmic Complexity
What is the big-o complexity of MongoDB lookup operation?
Say I have n records in my MongoDB collection 'A',
And n records in collection 'B', each B's document have foreign _id of A, and one specific tag eg "preOrder","directOrder", "pendingOrder"…
Fazal
- 300
- 2
- 14
3
votes
1 answer
How can I use MongoDB's aggregate with $lookup to replace an attribute that holds an id with the whole document?
I have two collections:
user:
{
"_id" : "9efb42e5-514d-44bd-a4b8-6f74e6313ec2",
"name" : "Haralt",
"age" : 21,
"bloodlineId" : "c59a2d02-f304-49a8-a52a-44018fc15fe6",
"villageId" : "foovillage"
}
bloodlines:
{
"_id" :…
xetra11
- 7,671
- 14
- 84
- 159
3
votes
1 answer
MongoDB Aggregation - $lookup performance
I'm using MongoDB 3.6 aggregation with lookup in order to Join two collections (users and subscriptionusers).
var UserSchema = mongoose.Schema({
email:{
type: String,
trim: true,
unique: true,
},
name: {
type: String,
…
esneyderp
- 111
- 1
- 12
2
votes
0 answers
Perform lookup on all dynamic reference fields if they exist
I have a rather complicated situation that I want to solve. I have a very dynamic model that allows to reference other objects (in the same collection). The reference may be a single value or an array of references. Also, the names are not known in…
OGordo
- 143
- 1
- 6
2
votes
1 answer
Lookup for documents and return only the missing values
I have 2 collections like that, being A a 1.5kk documents collection:
A
_id
relation: { alias, ref: 'B/<_id>' }
B
_id
name
I want to query for the elements in A, that aren't in B. This is what I get so far:
db.getCollection('A').aggregate([
{
…
Victor Ferreira
- 6,151
- 13
- 64
- 120
2
votes
0 answers
Can we apply Projection in model level which is applied where ever that model is accessed even in aggregate or $lookup
Mongoose provides us with the ability to apply Aggregation Hooks which works only when aggregation is applied to that particular model.
userSchema.post("aggregate", function() {
this.pipeline().push({$project: { _id: 1, firstName: 1, lastName: 1…
Fakhir Shad
- 1,071
- 8
- 20
2
votes
1 answer
MongoDB $lookup in an array of object with different value
I've got two MongoDB collections and i want to replace all the ID by image object.
Datset collection :
{
_id: 5d888b3a29cf9a5e93d80756,
date: 2019-09-23T11:33:00.000Z,
robot: { _id: 5d9c7caf0ad3ea493210527b, name: 'erx01' },
images:[
…
EyRaG _
- 23
- 3
1
vote
0 answers
MongoDb $Lookup doesn't work as expected in C#
I have a C# method that returns users' property data in a particular area using $geoNear and $project. I used the below pipeline to get the result.
var pipeline = new[]
{
new BsonDocument("$geoNear", new BsonDocument
…
Shehan V
- 164
- 1
- 14
1
vote
1 answer
How to get associated document who satisfy match object
In the following query, I want to fetch all verified students and their related meetings. but Trying to fetch all upcoming meetings which means meetings having at least one future date time. My writtten query fetches all verified students but also…
Mani
- 2,391
- 5
- 37
- 81
1
vote
1 answer
MongoDB aggregation make inner array in root
Hi I have two collection person and department. Those collection have the properties as below.
I want to aggregate and add a inner array in to the root of the document. Please check the result I need below:
person:
{
…
Vrangle
- 323
- 5
- 13
1
vote
1 answer
MongoDB - lookup - multiple collection - Result in one array
Site collection fields - _id, name
Node collection fields - _id, siteId, name
Device collection fields - _id, nodeId, name
Sensor collection fields - _id, deviceId, name
I am new with MongoDB, Expected Result (without duplicated data):
[{
…
Bhavin
- 179
- 1
- 2
- 13
1
vote
1 answer
MongoDB multiple subqueries
I'm kinda new to no-sql databases, so I have a question on subqueries here.
Let's imagine the following structure:
Type (_id, offerId)
Offer (_id, typeId, productId)
Product (_id, subId)
I need to find all types by subId.
I have no idea on how does…
Tyulpan Tyulpan
- 724
- 1
- 7
- 17
1
vote
1 answer
How to get list of id of all ROOT documents to pass to $lookup pipeline MongoDb
I have 2 collections:
users collection:
{
"_id": "1234141341"
"name": "David",
"is_active": True,
"age": 20
}
locations collection:
{
"owner": "1234141341"
"type": "Point"
"coordinates": [ 105.843111, 21.045752 ]
}
I…
Alexander Phung
- 75
- 1
- 9
1
vote
1 answer
Mongodb lookup array of elements with combined result
So these are my two documents
Order document:
{
"_id":"02a33b9a-284c-4869-885e-d46981fdd679",
"context":{
"products":[
{
"id": "e68fc86a-b4ad-4588-b182-ae9ee3db25e4",
"version":…
Ognjen Kljajic
- 37
- 5