MongoDB is a NoSQL database with the intent of storing billions of records. It offers the aggregation framework as a tool to manipulate and query records. This tag is intended to be used with question specific to this aggregation framework, since aggregation is too general.
Questions tagged [mongodb-aggregation]
147 questions
2
votes
0 answers
Combining results from different aggregate queries
If you have 3 different MongoDb Aggregate queries based on 3 different collections, each calculating a score for that Dept in a company, how does one combine / $project the results into 1 combined executive report by use of query, without storing…
Albert
- 81
- 4
2
votes
1 answer
Group by day/month/week basis on the date range
This is in reference to this question.
This is my data set:
[
{
"rating": 4,
"ceatedAt": ISODate("2016-08-08T15:32:41.262+0000")
},
{
"rating": 3,
"createdAt": ISODate("2016-08-08T15:32:41.262+0000")
},
{
"rating": 3,
…
nirvair
- 4,001
- 10
- 51
- 85
2
votes
1 answer
MongoDB join two collections using aggregation $lookup or populate in Node.js
Here are two collections' schema
var activitySchema = new Schema({
activity_id: {type: String, index: {unique: true}, required: true},
begin_date : String,
...
})
var registrationSchema = new Schema({
activity_id: {type:…
Eric Turner
- 41
- 1
- 5
2
votes
1 answer
Mongo Aggregation $filter on ISO date value
I have the following document
{
"_id": "57b4c5f0291ebb13110b888e",
"first": "John",
"last": "Smith",
"email": "John.Smith@gmail.com",
"fulfillments": [
{
"_id": "57b683e531a5a21679b78e6d",
"created_by_name": "John Smith",
…
TheJediCowboy
- 8,924
- 28
- 136
- 208
2
votes
1 answer
how to combine projection and pagination in mongodb?
I have a document structure such as this:
{
"name":"test",
"family":"test",
score:[
{
"point":3,
"des":"blah"
},
{
"point":4,
"des":"blahblah"
},
{
"point":5,
…
Navid_pdp11
- 3,487
- 3
- 37
- 65
2
votes
1 answer
C# MongoDb Project with DateTime.date
Given:
I've a mongodb collection with some data. One field is a DateTime field .
Now I want to aggregate the data for each day.
for this I created this aggregation
var result = collection
.Aggregate()
.Project(i =>…
Boas Enkler
- 12,264
- 16
- 69
- 143
2
votes
1 answer
Count ocurrence of two fields
I have this kind of documents in a MongoDb collection:
[
{
"_id": {
"id": 892,
"answer": "C",
"level": "regular"
},
"total": 4
},
{
"_id": {
"id": 891,
"answer": "Regular",
"level":…
viniciusbo
- 53
- 6
2
votes
1 answer
Boolean Expression with String Comparison in Mongodb?
$cond in mongodb is defined like this:
$cond: { if: { $gte: [ "$qty", 250 ] }, then: 30, else: 20 }
But, can we do that for a string ? I want to compare string value inside a document with regex, so something like this can work:
$cond: { if: {…
DennyHiu
- 4,861
- 8
- 48
- 80
1
vote
1 answer
mongoDB aggregate query returning results in reverse order
My aggregation pipeline on mongoDB is…
Sourabh Jain
- 55
- 1
- 4
1
vote
3 answers
Mongodb geonear and aggregate very slow
My current mongo version is 2.4.9 and collection have around 2.8millions rows. My query take super long to finish when using $geonear in the query.
Example of my collection
"loc" : {
"type" : "Point",
"coordinates" : [
100.46589473,…
Eric
- 1,547
- 2
- 18
- 34
1
vote
0 answers
Count mismatch in $substr aggregate function mongodb
i have some data where ISO date is getting stored as string and i am running $substr to get the count Match with substring in mongodb aggregation
but count mismatch is coming day by day. couldnot able to figure out why. database is in mlab.com which…
Priyanka D L
- 171
- 1
- 8
1
vote
2 answers
How to get the top five fastest ground speeds using mongodb
So I have this data imported from excel and I want to be able find the top five fastest speeds. I tried using the aggregate function but what was returned was 0.
db.planes.aggregate({
$group : {
_id : "$msg_dummy",
fastest :…
mike-gallego
- 706
- 2
- 12
- 27
1
vote
1 answer
How to Check current user's vote before votes are grouped and sumed in same aggregate function
var PostSchema = new mongoose.Schema({
item: {
type: mongoose.Schema.ObjectId,
ref: 'item',
required: true
},
user: {
type: mongoose.Schema.ObjectId,
ref: 'User',
required: true
},
vote: {
type:…
NoobSter
- 1,150
- 1
- 16
- 39
1
vote
2 answers
Max query in mongodb with where clause
I want create a MAX query in MongoDB with where clause.
I try this
db.Collection.aggregate({$group : {_id : "$P_ID", massi : {$max : "$b_val"}}},{P_ID:'XYZ',experiment:'abc'});
My WHERE clause is {P_ID:'XYZ',experiment:'abc'}
I don't why but this…
mongoDB
- 23
- 5
1
vote
2 answers
Mongodb group documents and limit each group
Considering those documents:
{
"Field1":"Test_1",
"Speaker":1,
"Listener":2,
"ListenTime": ISODate("2016-10-15T14:17:49.336Z")
},
{
"Field1":"Test_2",
"Speaker":1,
"Listener":2,
"ListenTime":…
Marco
- 656
- 9
- 28