My documents are organized this way:
{
"_id" : ObjectId("5ea899d7e7da54cabbc022e7"),
"date" : ISODate("2018-01-27T00:00:00Z"),
"vehicleid" : 32028,
"points" : [
{
"direction" : 225,
"location" : {
"type" : "Point",
"coordinates" : [
-3.801898,
-38.501078
]
},
"odometer" : 134746396,
"routecode" : 0,
"speed" : 0,
"deviceid" : 148590,
"metrictimestamp" : ISODate("2018-01-27T23:32:03Z")
}
Where points is an array of objects. I need to group this documents and return the amount of elements inside each array. I guess that is something like:
pipe = [
{
'$project':{
"_id":0
}
},
{
'$group':{
"_id":{
"vehicleid":"$vehicleid",
"date":"$date"
},'count':{'$size':'points'}
}
}
]
Detail: I need to run this on pymongo.
You have to use $sum to sum the size of each array like this
{
"$group": {
"_id": {
"vehicleid": "$vehicleid",
"date": "$date"
},
"count": { "$sum": { "$size": "$points" } }
}
}
You can use any of the following aggregation pipelines. You will get the size of the points array field. Each pipeline uses different approach, and the output details differ, but the size info will be same.
The code runs with PyMongo:
pipeline = [
{
"$unwind": "$points"
},
{
"$group": {
"_id": { "vehicleid": "$vehicleid", "date": "$date" },
"count": { "$sum": 1 }
}
}
]
pipeline = [
{
"$addFields": { "count": { "$size": "$points" } }
}
]
You can follow this code
$group : {
_id : {
"vehicleid":"$vehicleid",
"date":"$date"
count: { $sum: 1 }
}
}
Related
So I'm learning mongodb and I got a collection of writers to train.
Here I'm trying to count works by sorting them by country and gender of the author. This is what I accoplished so far:
db.writers.aggregate([
{ "$match": { "gender": {"$ne": male}}},
{ "$group": {
"_id": {
"country_id": "$country_id",
"type": "$type"
},
}},
{ "$group": {
"_id": "$_id.country_id",
"literary_work": {
"$push": {
"type": "$_id.type",
"count": { "$sum": "$type" }
}
},
"total": { "$sum": "$type" }
}},
{ "$sort": { "country_id": 1 } },
{ "$project": {
"literary_work": { "$slice": [ "$literary_work", 3 ] },
"total": { "$sum": "$type" }
}}
])
Sadly, the output that I get is not the one I'm expecting:
"_id" : GREAT BRITAIN,
"literary_work" : [
{
"type" : "POEM",
"count" : 0
},
{
"type" : "NOVEL",
"count" : 0
},
{
"type" : "SHORT STORY",
"count" : 0
}
],
"total" : 0
Could anyone tell me where do I insert the count stage or what is my mistake?)
upd:
Data sample:
{
"_id" : ObjectId("5f115c5d5f62f9f482cd7a49"),
"author" : George Sand,
"gender" : female,
"country_id" : FRANCE,
"title": "Consuelo",
"type" : "NOVEL",
}
Expected result (NB! this is a result for both genders):
{
"_id" : FRANCE,
"count" : 59.0,
"literary_work" : [
{
"type" : "POEM",
"count" : 14.0
},
{
"type" : "NOVEL",
"count" : 34.0
},
{
"type" : "SHORT STORY",
"count" : 11.0
}
]
}
Your implementation is correct way but there are missing things:
missed count in first $group
on the base of first group count it can count whole count of literary_work
and $project is not needed from your query
Corrected things in query,
db.writers.aggregate([
{
$match: {
gender: { $ne: "male" }
}
},
{
$group: {
_id: {
country_id: "$country_id",
type: "$type"
},
// missed this
count: { $sum: 1 }
}
},
{
$group: {
_id: "$_id.country_id",
// this count will be on the base of first group count
count: { $sum: "$count" },
literary_work: {
$push: {
type: "$_id.type",
// add count in inner count
count: "$count"
}
}
}
},
// corrected from country_id to _id
{
$sort: { "_id": 1 }
}
])
Working Playground: https://mongoplayground.net/p/JWP7qdDY6cc
I have some documents in a collection which looks like this
{
"_id" : "5a2e50b32d43ba00010041e5",
account_id:"23232323"
status:"accepted",
keyname:"java"
},
{
"_id" : "5a2e54332d43ba00010041e5",
account_id:"2323233"
status:"pending",
keyname:"java"
},
{
"_id" : "5a2e54332d43ba00010041e5",
account_id:"23232sdsd3"
status:"pending",
keyname:"Nodejs"
}
I need to get the counts of the pending and accepted status for each keyname for a particular account_id
eg: should give a result like this.
{
keyname:"java",
pending:10,
accepted:10
}
This is the code that I have tried out
db.getCollection("programs").aggregate([
{ "$match": { "account_id": "1" } },
{ "$group": { "_id": "$keyname", "count": { "$sum": 1 } } },
{ "$match": { "_id": { "$ne": null } } }
])
which gives a result like this
{
"_id" : "java",
"count" : 3.0
},
{
"_id" : "nodejs",
"count" : 3.0
},
{
"_id" : "C#",
"count" : 3.0
}
You can use below aggregation
db.collection.aggregate([
{ "$match": { "account_id": "1" } },
{ "$group": {
"_id": "$keyname",
"accepted": {
"$sum": {
"$cond": [
{ "$eq": ["$status", "accepted"] },
0,
1
]
}
},
"pending": {
"$sum": {
"$cond": [
{ "$eq": ["$status", "pending"] },
0,
1
]
}
}
}}
])
Mongo query generated out of java code:
{
"pipeline": [{
"$match": {
"Id": "09cd9a5a-85c5-4948-808b-20a52d92381a"
}
},
{
"$group": {
"_id": "$result",
"id": {
"$first": "$result"
},
"labelKey": {
"$first": {
"$ifNull": ["$result",
"$result"]
}
},
"value": {
"$sum": 1
}
}
}]
}
Field 'result' can have values like Approved, Rejected, null and "" (empty string). What I am trying to achieve is combining the count of both null and empty together.
So that the empty string Id will have the count of both null and "", which is equal to 4
I'm sure theres a more "proper" way but this is what i could quickly come up with:
[
{
"$group" : {
"_id" : "$result",
"id" : {
"$first" : "$result"
},
"labelKey" : {
"$first" : {
"$ifNull" : [
"$result",
"$result"
]
}
},
"value" : {
"$sum" : 1.0
}
}
},
{
"$group" : {
"_id" : {
"$cond" : [{
$or: [
{"$eq": ["$_id", "Approved"]},
{"$eq": ["$_id", "Rejected"]},
]}},
"$_id",
""
]
},
"temp" : {
"$push" : {
"_id" : "$_id",
"labelKey" : "$labelKey"
}
},
"count" : {
"$sum" : "$value"
}
}
},
{
"$unwind" : "$temp"
},
{
"$project" : {
"_id" : "$temp._id",
"labelKey": "$temp.labelKey",
"count" : "$count"
}
}
],
);
Due to the fact the second group is only on 4 documents tops i don't feel too bad about doing this.
I have used $facet.
The MongoDB stage $facet lets you run several independent pipelines within the stage of a pipeline, all using the same data. This means that you can run several aggregations with the same preliminary stages, and successive stages.
var queries = [{
"$match": {
"Id": "09cd9a5a-85c5-4948-808b-20a52d92381a"
}
},{
$facet: {//
"empty": [
{
$match : {
result : { $in : ['',null]}
}
},{
"$group" : {
"_id" : null,
value : { $sum : 1}
}
}
],
"non_empty": [
{
$match : {
result : { $nin : ['',null]}
}
},{
"$group" : {
"_id" : '$result',
value : { $sum : 1}
}
}
]
}
},
{
$project: {
results: {
$concatArrays: [ "$empty", "$non_empty" ]
}
}
}];
Output :
{
"results": [{
"_id": null,
"value": 52 // count of both '' and null.
}, {
"_id": "Approved",
"value": 83
}, {
"_id": "Rejected",
"value": 3661
}]
}
Changing the group by like below solved the problem
{
"$group": {
"_id": {
"$ifNull": ["$result", ""]
},
"id": {
"$first": "$result"
},
"labelKey": {
"$first": {
"$ifNull": ["$result",
"$result"]
}
},
"value": {
"$sum": 1
}
}
}
I am trying to calculate total value if that value exits. But query is not working 100%. So can somebody help me to solve this problem. Here my sample document. I have attached two documents. Please these documents & find out best solution
Document : 1
{
"_id" : 1"),
"message_count" : 4,
"messages" : {
"data" : [
{
"id" : "11",
"saleValue": 1000
},
{
"id" : "112",
"saleValue": 1400
},
{
"id" : "22",
},
{
"id" : "234",
"saleValue": 111
}
],
},
"createdTime" : ISODate("2018-03-18T10:18:48.000Z")
}
Document : 2
{
"_id" : 444,
"message_count" : 4,
"messages" : {
"data" : [
{
"id" : "444",
"saleValue" : 2060
},
{
"id" : "444",
},
{
"id" : 234,
"saleValue" : 260
},
{
"id" : "34534",
}
]
},
"createdTime" : ISODate("2018-03-18T03:11:50.000Z")
}
Needed Output:
{
total : 4831
}
My query :
db.getCollection('myCollection').aggregate([
{
"$group": {
"_id": "$Id",
"totalValue": {
$sum: {
$sum: "$messages.data.saleValue"
}
}
}
}
])
So please if possible help me to solve this problem. Thanks in advance
It's not working correctly because it is aggregating all the documents in the collection; you are grouping on a constant "_id": "tempId", you just need to reference the correct key by adding the $ as:
db.getCollection('myCollection').aggregate([
{ "$group": {
"_id": "$tempId",
"totalValue": {
"$sum": { "$sum": "$messages.data.saleValue" }
}
} }
])
which in essence is a single stage pipeline version of an aggregate operation with an extra field that holds the sum expression before the group pipeline then calling that field as the $sum operator in the group.
The above works since $sum from MongoDB 3.2+ is available in both the $project and $group stages and when used in the $project stage, $sum returns the sum of the list of expressions. The expression "$messages.data.value" returns a list of numbers [120, 1200] which are then used as the $sum expression:
db.getCollection('myCollection').aggregate([
{ "$project": {
"values": { "$sum": "$messages.data.value" },
"tempId": 1,
} },
{ "$group": {
"_id": "$tempId",
"totalValue": { "$sum": "$values" }
} }
])
You can add a $unwind before your $group, in that way you will deconstructs the data array, and then you can group properly:
db.myCollection.aggregate([
{
"$unwind": "$messages.data"
},
{
"$group": {
"_id": "tempId",
"totalValue": {
$sum: {
$sum: "$messages.data.value"
}
}
}
}
])
Output:
{ "_id" : "tempId", "totalValue" : 1320 }
db.getCollection('myCollection').aggregate([
{
$unwind: "$messages.data",
$group: {
"_id": "tempId",
"totalValue": { $sum: "$messages.data.value" }
}
}
])
$unwind
According to description as mentioned into above question, as a solution please try executing following aggregate query
db.myCollection.aggregate(
// Pipeline
[
// Stage 1
{
$unwind: {
path: '$messages.data'
}
},
// Stage 2
{
$group: {
_id: {
pageId: '$pageId'
},
total: {
$sum: '$messages.data.saleValue'
}
}
},
// Stage 3
{
$project: {
pageId: '$_id.pageId',
total: 1,
_id: 0
}
}
]
);
You can do it without using $group. Grouping made other data to be managed and addressed. So, I prefer using $sum and $map as shown below:
db.getCollection('myCollection').aggregate([
{
$addFields: {
total: {
$sum: {
$map: {
input: "$messages.data",
as: "message",
in: "$$message.saleValue",
},
},
},
},
},
}
])
I'm pretty new to MongoDB, and having some problems getting my query as I want it. The documents contain "errors" that have happened a specific time. The result I want from the query is an error count for each month per user. This I have already figured out, but additionally I want the total errorcount per user.
This is what I've got so far:
db.Logger.aggregate([
{ "$group": {
"_id": {
"name": "$name",
"month": { "$month": "$errorTime" }
},
"totalErrors": { "$sum": 1 }
}},
{ $group :
{ _id: { name : "$_id.name"},
errors: { $addToSet: { totalErrors: { errorsThisMonth: "$totalErrors", currentMonth : "$_id.month" } } },
}
}
])
The result is:
{
"_id" : {
"name" : "abhos"
},
"errors" : [
{
"totalErrors" : {
"errorsThisMonth" : 6,
"currentMonth" : 2
}
},
{
"totalErrors" : {
"errorsThisMonth" : 6,
"currentMonth" : 1
}
}
]
},
Will it be possible to get what I want by adding to that query?
All you need is an additional $sum in your second $group:
db.Logger.aggregate([
{ "$group": {
"_id": {
"name": "$name",
"month": { "$month": "$errorTime" }
},
"totalErrors": { "$sum": 1 }
}},
{ "$group": {
"_id": "$_id.name",
"errors": {
"$addToSet": {
"errorsThisMonth": "$totalErrors",
"currentMonth" : "$_id.month"
}
},
"totalErrors": { "$sum": "$totalErrors" }
}}
])
Also you have a few extra document levels you do not need in there, such as extra fields under the _id and the "errors" "set" produced in the grouping. This output is just a little different without those additional levels:
{
"_id": "abhos"
"errors" : [
{
"errorsThisMonth" : 6,
"currentMonth" : 2
},
{
"errorsThisMonth" : 6,
"currentMonth" : 1
}
],
"totalErrors": 12
},