I'm creating a MongoDB aggregation pipeline and I'm stuck at this stage:
$group: {
_id: {checkType: "$_id.checkType", resultCode: "$_id.resultCode"},
count: { $sum: "$count" },
ctv: { $sum: "$ctv" },
perc:{$multiply:[{$divide:["$ctv","$count"]},100]},
weight: { $divide: [ "$ctv", "$count"] },
details: { $push: "$$ROOT" }
}
It gives the error "The $multiply accumulator is a unary operator". Similarly if I remove the line with $multiply I get "The $divide accumulator is a unary operator" on the subsequent line. I cannot find a description for this error on the Net. What's wrong in my sintax?
The arithmetic operators cannot be used as $group accumulators. Move them to another $project pipeline stage as:
db.collection.aggregate([
{ "$group": {
"_id": { "checkType": "$_id.checkType", "resultCode": "$_id.resultCode" },
"count": { "$sum": "$count" },
"ctv": { "$sum": "$ctv" },
"details": { "$push": "$$ROOT" }
} },
{ "$project": {
"count": 1,
"details": 1,
"ctv": 1,
"perc": { "$multiply": [ { "$divide": ["$ctv","$count"] }, 100 ] },
"weight": { "$divide": ["$ctv", "$count"] },
} }
])
or
if using MongoDB 3.4 and above, use $addFields instead of $project
db.collection.aggregate([
{ "$group": {
"_id": { "checkType": "$_id.checkType", "resultCode": "$_id.resultCode" },
"count": { "$sum": "$count" },
"ctv": { "$sum": "$ctv" },
"details": { "$push": "$$ROOT" }
} },
{ "$addFields": {
"perc": { "$multiply": [ { "$divide": ["$ctv","$count"] }, 100 ] },
"weight": { "$divide": ["$ctv", "$count"] },
} }
])
Related
I'm new in mongoDB.
This is one example of record from collection:
{
supplier: 1,
type: "sale",
items: [
{
"_id": ObjectId("60ee82dd2131c5032342070f"),
"itemBuySum": 10
},
{
"_id": ObjectId("60ee82dd2131c50323420710"),
"itemBuySum": 10,
},
{
"_id": ObjectId("60ee82dd2131c50323420713"),
"itemBuySum": 10
},
{
"_id": ObjectId("60ee82dd2131c50323420714"),
"itemBuySum": 20
}
]
}
I need to group by TYPE field and get the SUM. This is output I need:
{
supplier: 1,
sales: 90,
returns: 170
}
please check Mongo playground for better understand. Thank you!
$match - Filter documents.
$group - Group by type and add item into data array which leads to the result like:
[
[/* data 1 */],
[/* data 2 */]
]
$project - Decorate output document.
3.1. First $reduce is used to flatten the nested array to a single array (from Result (2)) via $concatArrays.
3.2. Second $reduce is used to aggregate $sum the itemBuySum.
db.collection.aggregate({
$match: {
supplier: 1
},
},
{
"$group": {
"_id": "$type",
"supplier": {
$first: "$supplier"
},
"data": {
"$push": "$items"
}
}
},
{
"$project": {
_id: 0,
"supplier": "$supplier",
"type": "$_id",
"returns": {
"$reduce": {
"input": {
"$reduce": {
input: "$data",
initialValue: [],
in: {
"$concatArrays": [
"$$value",
"$$this"
]
}
}
},
"initialValue": 0,
"in": {
$sum: [
"$$value",
"$$this.itemBuySum"
]
}
}
}
}
})
Sample Mongo Playground
db.collection.aggregate([
{
$match: {
supplier: 1
},
},
{
"$group": {
"_id": "$ID",
"supplier": {
"$first": "$supplier"
},
"sale": {
"$sum": {
"$cond": {
"if": {
"$eq": [
"$type",
"sale"
]
},
"then": {
"$sum": "$items.itemBuySum"
},
"else": {
"$sum": 0
}
}
}
},
"returns": {
"$sum": {
"$sum": {
"$cond": {
"if": {
"$eq": [
"$type",
"return"
]
},
"then": {
"$sum": "$items.itemBuySum"
},
"else": {
"$sum": 0
}
}
}
}
}
}
},
{
"$project": {
_id: 0,
supplier: 1,
sale: 1,
returns: 1
}
}
])
I have a query and when I use a $group a error shows "the field "$name must be an accumulator object", if if remove the filed "$name" all works well and i have tried to use only "name" instead of "$name" and the error continues.
User.aggregate([
{
$match: {
"storeKey": req.body.store
}
},
{
$group: {
"_id": "$_id",
"name": "$name",
"count": {
"$sum": 1
},
"totalValue": {
"$sum": "$value"
}
}
},
{
$sort: sort
},
{
$skip: req.body.limit * req.body.page
},
{
$limit: req.body.limit
}
])...
There are some aggregation operators that can only be used in $group aggregation and named as $group accumulators
Just as you used $sum here you have to use for the name key as well
{ "$group": {
"_id": "$_id",
"name": { "$first": "$name" }, //$first accumulator
"count": { "$sum": 1 }, //$sum accumulator
"totalValue": { "$sum": "$value" } //$sum accumulator
}}
Accumulator is like array of Elements its Accumulates as Array.
$first -> gives 1st name that goes in the group of names
Example:
so if you have $_id same but different name ["Darik","John"]
specifying $first will give Darik & similarly $last will give John
$group: {
_id:"$_id",
"name" :{ $last: '$name' },
"count" : { $sum: 1 },
"totalValue": { "$sum": "$value" }
}
db.faq_feedback.aggregate({
$lookup:{
"from":"faq",
"localField":"question_id",
"foreignField":"_id",
"as":"faq"
}
},
{
$unwind:"$faq"
},
{
$project:{
"question_id":1,
"lang":"$faq.lang",
"feedback":"$faq.feedback",
"question":"$faq.question",
"yes":{
"$cond":[
{
"$eq":[
"$feedback",
"yes"
]
},
1,
0
]
},
"no":{
"$cond":[
{
"$eq":[
"$feedback",
"no"
]
},
1,
0
]
}
}
},
{
$group:{
"_id":"$question_id",
"yes":{
"$sum":"$yes"
},
"no":{
"$sum":"$no"
},
"question":{"$first":"$question"},
"lang":{"$first":"$lang"}
}
},
{
$limit:10000
},
{
$skip:0
})
I want to write a group by query to written active user and total count(both active and inactive) grouped by a date column in mongodb. I am able to run them as two separate scripts but how to retrieve the same information in one script
db.user.aggregate(
{
"$match": { 'phoneInfo.verifiedFlag': true}
},
{
"$project": {
yearMonthDayUTC: { $dateToString: { format: "%Y-%m-%d", date: "$createdOn" } }
}
},
{
"$group": {
"_id": {day: "$yearMonthDayUTC"},
count: {
"$sum": 1
}
}
},
{
$sort: {
"_id.day": 1,
}
})
You can use the $cond operator in your group to create a conditional count as follows (assuming the inactive/active values are in a field called status):
db.user.aggregate([
{ "$match": { 'phoneInfo.verifiedFlag': true} },
{
"$group": {
"_id": { "$dateToString": { "format": "%Y-%m-%d", "date": "$createdOn" } },
"total": { "$sum": 1 },
"active_count": {
"$sum": {
"$cond": [ { "$eq": [ "$status", "active" ] }, 1, 0 ]
}
},
"inactive_count": {
"$sum": {
"$cond": [ { "$eq": [ "$status", "inactive" ] }, 1, 0 ]
}
}
}
},
{ "$sort": { "_id": 1 } }
])
For different values you can adapt the following pipeline:
db.user.aggregate([
{ "$match": { 'phoneInfo.verifiedFlag': true} },
{
"$group": {
"_id": {
"day": {
"$dateToString": {
"format": "%Y-%m-%d",
"date": "$createdOn"
}
},
"status": { "$toLower": "$status" }
},
"count": { "$sum": 1 }
}
},
{
"$group": {
"_id": "$_id.day",
"counts": {
"$push": {
"status": "$_id.status",
"count": "$count"
}
}
}
},
{ "$sort": { "_id": 1 } }
])
Collection exists as below:
[
{"currentLocation": "Chennai", "baseLocation": "Bengaluru"},
{"currentLocation": "Chennai", "baseLocation": "Bengaluru"},
{"currentLocation": "Delhi", "baseLocation": "Bengaluru"},
{"currentLocation": "Chennai", "baseLocation": "Chennai"}
]
Expected Output:
[
{"city": "Chennai", "currentLocationCount": 3, "baseLocationCount": 1},
{"city": "Bengaluru", "currentLocationCount": 0, "baseLocationCount": 3},
{"city": "Delhi", "currentLocationCount": 1, "baseLocationCount": 0}
]
What I have tried is:
db.getCollection('users').aggregate([{
$group: {
"_id": "$baselocation",
baseLocationCount: {
$sum: 1
}
},
}, {
$project: {
"_id": 0,
"city": "$_id",
"baseLocationCount": 1
}
}])
Got result as:
[
{"city": "Chennai", "baseLocationCount": 1},
{"city": "Bengaluru", "baseLocationCount": "3"}
]
I'm not familiar with mongo, so any help?
MongoDB Version - 3.4
Neil Lunn and myself had a lovely argument over this topic the other day which you can read all about here: Group by day with Multiple Date Fields.
Here are two solutions to your precise problem.
The first one uses the $facet stage. Bear in mind, though, that it may not be suitable for large collections because $facet produces a single (potentially huge) document that might be bigger than the current MongoDB document size limit of 16MB (which only applies to the result document and wouldn't be a problem during pipeline processing anyway):
collection.aggregate(
{
$facet:
{
"current":
[
{
$group:
{
"_id": "$currentLocation",
"currentLocationCount": { $sum: 1 }
}
}
],
"base":
[
{
$group:
{
"_id": "$baseLocation",
"baseLocationCount": { $sum: 1 }
}
}
]
}
},
{ $project: { "result": { $setUnion: [ "$current", "$base" ] } } }, // merge results into new array
{ $unwind: "$result" }, // unwind array into individual documents
{ $replaceRoot: { newRoot: "$result" } }, // get rid of the additional field level
{ $group: { "_id": "$_id", "currentLocationCount": { $sum: "$currentLocationCount" }, "baseLocationCount": { $sum: "$baseLocationCount" } } }, // group into final result)
{ $project: { "_id": 0, "city": "$_id", "currentLocationCount": 1, "baseLocationCount": 1 } } // group into final result
)
The second one works based on the $map stage instead:
collection.aggregate(
{
"$project": {
"city": {
"$map": {
"input": [ "current", "base" ],
"as": "type",
"in": {
"type": "$$type",
"name": {
"$cond": {
"if": { "$eq": [ "$$type", "current" ] },
"then": "$currentLocation",
"else": "$baseLocation"
}
}
}
}
}
}
},
{ "$unwind": "$city" },
{
"$group": {
"_id": "$city.name",
"currentLocationCount": {
"$sum": {
"$cond": {
"if": { "$eq": [ "$city.type", "current" ] },
"then": 1,
"else": 0
}
}
},
"baseLocationCount": {
"$sum": {
"$cond": {
"if": { "$eq": [ "$city.type", "base" ] },
"then": 1,
"else": 0
}
}
}
}
}
)
I have documents like:
{
"platform":"android",
"install_date":20151029
}
platform - can have one value from [android|ios|kindle|facebook ] .
install_date - there are many install_dates
There are also many fields.
Aim : I am calculating installs per platform on particular date.
So I am using group by in aggregation framework and make counts by platform. Document should look like like:
{
"install_date":20151029,
"platform" : {
"android":1000,
"ios": 2000,
"facebook":1500
}
}
I have done like:
db.collection.aggregate([
{
$group: {
_id: { platform: "$platform",install_date:"$install_date"},
count: { "$sum": 1 }
}
},
{
$group: {
_id: { install_date:"$_id.install_date"},
platform: { $push : {platform :"$_id.platform", count:"$count" } }
}
},
{
$project : { _id: 0, install_date: "$_id.install_date", platform: 1 }
}
])
which Gives document like:
{
"platform": [
{
"platform": "facebook",
"count": 1500
},
{
"platform": "ios",
"count": 2000
},
{
"platform": "android",
"count": 1000
}
],
"install_date": 20151027
}
Problem:
Projecting array to single object as "platform"
With MongoDb 3.4 and newer, you can leverage the use of $arrayToObject operator to get the desired result. You would need to run the following aggregate pipeline:
db.collection.aggregate([
{ "$group": {
"_id": {
"date": "$install_date",
"platform": { "$toLower": "$platform" }
},
"count": { "$sum": 1 }
} },
{ "$group": {
"_id": "$_id.date",
"counts": {
"$push": {
"k": "$_id.platform",
"v": "$count"
}
}
} },
{ "$addFields": {
"install_date": "$_id",
"platform": { "$arrayToObject": "$counts" }
} },
{ "$project": { "counts": 0, "_id": 0 } }
])
For older versions, take advantage of the $cond operator in the $group pipeline step to evaluate the counts based on the platform field value, something like the following:
db.collection.aggregate([
{ "$group": {
"_id": "$install_date",
"android_count": {
"$sum": {
"$cond": [ { "$eq": [ "$platform", "android" ] }, 1, 0 ]
}
},
"ios_count": {
"$sum": {
"$cond": [ { "$eq": [ "$platform", "ios" ] }, 1, 0 ]
}
},
"facebook_count": {
"$sum": {
"$cond": [ { "$eq": [ "$platform", "facebook" ] }, 1, 0 ]
}
},
"kindle_count": {
"$sum": {
"$cond": [ { "$eq": [ "$platform", "kindle" ] }, 1, 0 ]
}
}
} },
{ "$project": {
"_id": 0, "install_date": "$_id",
"platform": {
"android": "$android_count",
"ios": "$ios_count",
"facebook": "$facebook_count",
"kindle": "$kindle_count"
}
} }
])
In the above, $cond takes a logical condition as it's first argument (if) and then returns the second argument where the evaluation is true (then) or the third argument where false (else). This makes true/false returns into 1 and 0 to feed to $sum respectively.
So for example, if { "$eq": [ "$platform", "facebook" ] }, is true then the expression will evaluate to { $sum: 1 } else it will be { $sum: 0 }