Considering the following document structure:
{_id: 1, name: 'joe', snapshot: null, age: 30}
{_id: 2, name: 'joe', snapshot: 'snapshot1', age: 30}
{_id: 3, name: 'joe', snapshot: 'snapshot15', age: 30}
{_id: 4, name: 'joe', snapshot: 'snapshot23', age: 30}
How would I perform a query that groups on the name field and adds an additional field that is a count of the remaining records containing subtree: 'additionalinfo'. It would look like this:
{_id: 1, name: 'joe', snapcount: 3, age: 30}
I've been able to group using aggregations but I can't quite get it like this.
My own solution:
I ultimately restructured my data to look like this instead:
{
_id: 1,
name: 'joe',
snapshots: [
{name: 'snap17', id: 1},
{name: 'snap15', id: 2},
{name: 'snap14', id: 3}
],
age: 30
}
This allows me to just check snapshots.length to solve my original problem. However; the answers in this post where very helpful and answered the original question.
Adding another aggregation query to do it: playground link: try it
db.collection.aggregate([
{
$match: {
"snapshot": {
$exists: true,
$ne: null
}
}
},
{
$group: {
_id: "$name",
snapcount: {
$sum: 1
},
age: {
"$first": "$age"
},
name: {
"$first": "$name"
}
}
},
{
"$unset": "_id"
}
])
Based on the comments, the query worked for OP:
db.collection.aggregate([
{
$match: {
"snapshot": {
$exists: true,
$ne: null
}
}
},
{
$group: {
_id: "$name",
snapcount: {
$sum: 1
},
age: {
"$first": "$age"
},
name: {
"$first": "$name"
},
id: {
"$first": "$_id"
}
}
},
{
"$unset": "_id"
}
])
Here's one way you could do it.
db.collection.aggregate([
{
"$group": {
"_id": "$name",
"name": {"$first": "$name"},
"age": {"$first": "$age"},
"snapcount": {
"$sum": {
"$cond": [
{"$eq": [{"$type": "$snapshot"}, "string"]},
1,
0
]
}
}
}
},
{"$unset": "_id"}
])
Try it on mongoplayground.net.
Related
simple collection:
[
{
_id: '123',
name: 'product1',
quantity: 10
},{
_id: '456',
name: 'product2',
quantity: 20
},{
_id: '789',
name: 'product1',
quantity: 30
},{
_id: '145',
name: 'product3',
quantity: 30
}
]
what im trying to get:
[
{
_id: 'product1',
quantity: 40
},{
_id:'product2',
quantity: 20
}
]
I want to filter by product1 and product2 and group by the 2 products with the total quantity.
what i tried:
db.CustomerOrders.aggregate([
{
"$match":{
"$or":[{"name":"product1"},{"name": "product2"}
]}},
{
"$group": {_id:"$name", quantity:{$sum:"$quantity"}}
}
}])
Code doesnt seem to work
Use $in in your $match stage.
db.collection.aggregate([
{
"$match": {
name: {
$in: [
"product1",
"product2"
]
}
}
},
{
$group: {
_id: "$name",
quantity: {
$sum: "$quantity"
}
}
}
])
Mongo Playground
db.setting.aggregate([
{
$match: {
status: true,
deleted_at: 0,
_id: {
$in: [
ObjectId("5c4ee7eea4affa32face874b"),
ObjectId("5ebf891245aa27c290672325")
]
}
}
},
{
$lookup: {
from: "site",
localField: "_id",
foreignField: "admin_id",
as: "data"
}
},
{
$project: {
name: 1,
status: 1,
price: 1,
currency: 1,
numberOfRecord: {
$size: "$data"
}
}
},
{
$sort: {
numberOfRecord: 1
}
}
])
how to push the currency into price object using project please guide thanks a lot, also eager to know what is difference between $addtoSet and $push, what is good option to opt it from project or fix it from $addField
https://mongoplayground.net/p/RiWnnRtksb4
Output should be like this:
[
{
"_id": ObjectId("5ebf891245aa27c290672325"),
"currency": "USD",
"name": "Menz",
"numberOfRecord": 0,
"price": {
"numberDecimal": "20",
"currency": "USD",
},
"status": true
},
{
"_id": ObjectId("5c4ee7eea4affa32face874b"),
"currency": "USD",
"name": "Dave",
"numberOfRecord": 2,
"price": {
"numberDecimal": "10",
"currency": "USD"
},
"status": true
}
]
You can insert a field into an object with project directly, like this (field price):
$project: {
name: 1,
status: 1,
price: {
numberDecimal: "$price.numberDecimal",
currency: "$currency"
},
numberOfRecord: {
$size: "$data"
}
}
By doing it with project, there is no need to use $addField.
For the difference between $addToSet and $push, read this great answer.
You can just set the object structure while projecting, so in this case there's no need for either $push or $addToSet.
{
$project: {
name: "1",
status: 1,
price: {
currency: "$currency",
numberDecimal: "$price.numberDecimal"
},
currency: 1,
numberOfRecord: {
$size: "$data",
}
}
}
Now the difference between $push and $addToSet is pretty trivial and derived from the name, $push saves all items while $addToSet will just create a set of them, for example:
input:
[
//doc1
{
item: 1
},
//doc2
{
item: 2
},
//doc3
{
item: 1
}
]
Now this:
{
$group: {
_id: null,
items: {$push: "$item"}
}
}
Will result in:
{_id: null, items: [1, 2, 1]}
While:
{
$group: {
_id: null,
items: {$addToSet: "$item"}
}
}
Will result in:
{_id: null, items: [1, 2]}
Given the following data, I'm trying to get an average of all their ages, at the same time I want to return an array of their names. Ideally, I want to do this in just one query but can't seem to figure it out.
Data:
users:[
{user:{
id: 1,
name: “Bob”,
age: 23
}},
{user:{
id: 1,
name: “Susan”,
age: 32
}},
{user:{
id: 2,
name: “Jeff”,
age: 45
}
}]
Query:
var dbmatch = db.users.aggregate([
{$match: {"id" : 1}},
{$group: {_id: null, avg_age: { $avg: "$age" }}},
{$group: {_id : { name: "$name"}}}
)]
Running the above groups one at a time outputs the results I expect, either an _id of null and an average of 27.5, or an array of the names.
When I combine them as you see above using a comma, I get:
Issue Generated Code:
[ { _id: {name: null } } ]
Expected Generated Code:
[
{name:"Bob"},
{name:"Susan"},
avg_age: 27.5
]
Any help would be greatly appreciated!
Not sure if this is exactly what you want, but this query
db.users.aggregate([
{
$match: {
id: 1
}
},
{
$group: {
_id: "$id",
avg_age: {
$avg: "$age"
},
names: {
$push: {
name: "$name"
}
}
}
},
{
$project: {
_id: 0
}
}
])
Results in this result:
[
{
"avg_age": 27.5,
"names": [
{
"name": "Bob"
},
{
"name": "Susan"
}
]
}
]
This will duplicate names, so if there are two documents with the name Bob, it will be two times in the array. If you don't want duplicates, change $push to $addToSet.
Also, if you want names to be just an array of names instead of objects, change names query to
names: {
$push: "$name"
}
This will result in
[
{
"avg_age": 27.5,
"names": ["Bob", "Susan"]
}
]
Hope it helps,
Tomas :)
You can use $facet aggregation to run the multiple queries at once
db.collection.aggregate([
{ "$facet": {
"firstQuery": [
{ "$match": { "id": 1 }},
{ "$group": {
"_id": null,
"avg_age": { "$avg": "$age" }
}}
],
"secondQuery": [
{ "$match": { "id": 1 }},
{ "$group": { "_id": "$name" }}
]
}}
])
I have a query using $lookup that "join" two models and $project to select all fields that i need only, and in that $project I need to $sum a value called totalValue but only return zero:
My query
User.aggregate([{
$match: {
storeKey: req.body.store,
}
},
{
$group: {
_id: {
id: "$_id",
name: "$name",
cpf: "$cpf",
phone: "$phone",
email: "$email",
birthday: "$birthday",
lastName: "$lastname"
},
totalServices: {
$sum: "$services"
},
}
},
{
$lookup: {
from: "schedules",
"let": { "id": "$_id.phone" },
"pipeline": [
{ "$match": { "$expr": { "$eq": ["$customer.phone", "$$id"] }}},
{ "$project": { "scheduleStart": 1, "scheduleEnd": 1 }}
],
"as": "user_detail"
}
},
{
$project: {
_id: 1,
name: 1,
name: 1,
cpf: 1,
phone: 1,
email: 1,
birthday: 1,
totalServices: 1,
totalValue: { $sum : "$user_detail.value" }, // here only return zero
count: {
$sum: 1
},
user_detail: 1
}
},
You need to $project your value field in the user_details projection to get it in the next aggregation stage
{ "$project": { "scheduleStart": 1, "scheduleEnd": 1, "value": 1 }}
Here's my problem:
Model:
{ application: "abc", date: Time.now, status: "1" user_id: [ id1, id2,
id4] }
{ application: "abc", date: Time.yesterday, status: "1", user_id: [
id1, id3, id5] }
{ application: "abc", date: Time.yesterday-1, status: "1", user_id: [
id1, id3, id5] }
I need to count the unique number of user_ids in a period of time.
Expected result:
{ application: "abc", status: "1", unique_id_count: 5 }
I'm currently using the aggregation framework and counting the ids outside mongodb.
{ $match: { application: "abc" } }, { $unwind: "$users" }, { $group:
{ _id: { status: "$status"},
users: { $addToSet: "$users" } } }
My arrays of users ids are very large, so I have to iterate the dates or I'll get the maximum document limit (16mb).
I could also $group by
{ year: { $year: "$date" }, month: { $month: "$date" }, day: {
$dayOfMonth: "$date" }
but I also get the document size limitation.
Is it possible to count the set size in mongodb?
thanks
The following will return number of uniqueUsers per application. This will apply an group operation to a result of a group operation by using pipeline feature of mongodb.
{ $match: { application: "abc" } },
{ $unwind: "$users" },
{ $group: { _id: "$status", users: { $addToSet: "$users" } } },
{ $unwind:"$users" },
{ $group : {_id : "$_id", count : {$sum : 1} } }
Hopefully this will be done in an easier way in the following releases of mongo by a command which gives the size of an array under a projection. {$project: {id: "$_id", count: {$size: "$uniqueUsers"}}}
https://jira.mongodb.org/browse/SERVER-4899
Cheers
Sorry I'm a little late to the party. Simply grouping on the 'user_id' and counting the result with a trivial group works just fine and doesn't run into doc size limits.
[
{$match: {application: 'abc', date: {$gte: startDate, $lte: endDate}}},
{$unwind: '$user_id'},
{$group: {_id: '$user_id'}},
{$group: {_id: 'singleton', count: {$sum: 1}}}
];
Use $size to get the size of set.
[
{
$match: {"application": "abc"}
},
{
$unwind: "$user_id"
},
{
$group: {
"_id": "$status",
"application": "$application",
"unique_user_id": {$addToSet: "$user_id"}
}
},
{
$project:{
"_id": "$_id",
"application": "$application",
"count": {$size: "$unique_user_id"}
}
}
]