I am quite new to MongoDB. Hopefully I am using the correct terminology to express my problem.
I have the following collection:
Data collection
{
"name":"ABC",
"resourceId":"i-1234",
"volumeId":"v-1234",
"data":"11/6/2013 12AM",
"cost": 0.5
},
{
"name":"ABC",
"resourceId":"v-1234",
"volumeId":"",
"data":"11/6/2013 2AM",
"cost": 1.5
}
I want to query the collection such that if a volumeId matches with another entries resourceId, then sum up the corresponding resourceId's cost together.
As a result, the cost would be 2.0 in this case.
Basically I want to match the volumeId of one entry to the resourceId of another entry and sum the costs if matched.
I hope I have explained my problem properly. Any help is appreciated. Thanks
Try this aggregation query:
db.col.aggregate([
{
$project: {
resourceId: 1,
volumeId: 1,
cost: 1,
match: {
$cond: [
{$eq: ["$volumeId", ""]},
"$resourceId",
"$volumeId"
]
}
}
},
{
$group: {
_id: '$match',
cost: {$sum: '$cost'},
resId: {
$addToSet: {
$cond: [
{$eq: ['$match', '$resourceId']},
null,
'$resourceId'
]
}
}
}
},
{$unwind: '$resId'},
{$match: {
resId: {
$ne: null
}
}
},
{
$project: {
resourseId: '$resId',
cost: 1,
_id: 0
}
}
])
And you will get the following:
{ "cost" : 2, "resourseId" : "i-1234" }
This is assuming the statement I wrote in the comment is true.
Related
I have this collection(some irrelevant fields were omitted for brevity):
clients: {
userId: ObjectId,
clientSalesValue: Number,
currentDebt: Number,
}
Then I have this query that matches all the clients for a specific user, then calculates the sum of all debts and sales and put those results in a separate field each of them:
await clientsCollection.aggregate([
{
$match: { userId: new ObjectId(userId) }
},
{
$group: {
_id: null,
totalSalesValue: { $sum: '$clientSalesValue' },
totalDebts: { $sum: '$currentDebt' },
}
},
{
$unset: ['_id']
}
]).exec();
This works as expected, it returns an array with only one item which is an object, but now I need to also include in that resultant object a field for the amount of debtors, that is for the amount of clients that have currentDebt > 0, how can I do that is the same query? is it possible?
PD: I cannot modify the $match condition, it need to always return all the clients for the corresponding users.
To include a count of how many matching documents have a positive currentDebt, you can use the $sum and $cond operators like so:
await clientsCollection.aggregate([
{
$match: { userId: new ObjectId(userId) }
},
{
$group: {
_id: null,
totalSalesValue: { $sum: '$clientSalesValue' },
totalDebts: { $sum: '$currentDebt' },
numDebtors: {
$sum: {
$cond: [{ $gt: ['$currentDebt', 0] }, 1, 0]
}
},
}
},
{
$unset: ['_id']
}
]).exec();
I have an issue that need to insert index number when get data. First i have this data for example:
[
{
_id : 616efd7e56c9530018e318ac
student : {
name: "Alpha"
email: null
nisn: "0408210001"
gender : "female"
}
},
{
_id : 616efd7e56c9530018e318af
student : {
name: "Beta"
email: null
nisn: "0408210001"
gender : "male"
}
}
]
and then i need the output like this one:
[
{
no:1,
id:616efd7e56c9530018e318ac,
name: "Alpha",
nisn: "0408210001"
},
{
no:2,
id:616efd7e56c9530018e318ac,
name: "Beta",
nisn: "0408210002"
}
]
i have tried this code but almost get what i expected.
{
'$project': {
'_id': 0,
'id': '$_id',
'name': '$student.name',
'nisn': '$student.nisn'
}
}
but still confuse how to add the number of index. Is it available to do it in $project or i have to do it other way? Thank you for the effort to answer.
You can use $unwind which can return an index, like this:
db.collection.aggregate([
{
$group: {
_id: 0,
data: {
$push: {
_id: "$_id",
student: "$student"
}
}
}
},
{
$unwind: {path: "$data", includeArrayIndex: "no"}
},
{
"$project": {
"_id": 0,
"id": "$data._id",
"name": "$data.student.name",
"nisn": "$data.student.nisn",
"no": {"$add": ["$no", 1] }
}
}
])
You can see it works here .
I strongly suggest to use a $match step before these steps, otherwise you will group your entire collection into one document.
You need to run a pipeline with a $setWindowFields stage that allows you to add a new field which returns the position of a document (known as the document number) within a partition. The position number creation is made possible by the $documentNumber operator only available in the $setWindowFields stage.
The partition could be an extra field (which is constant) that can act as the window partition.
The final stage in the pipeline is the $replaceWith step which will promote the student embedded document to the top-level as well as replacing all input documents with the specified document.
Running the following aggregation will yield the desired results:
db.collection.aggregate([
{ $addFields: { _partition: 'students' }},
{ $setWindowFields: {
partitionBy: '$_partition',
sortBy: { _id: -1 },
output: { no: { $documentNumber: {} } }
} },
{ $replaceWith: {
$mergeObjects: [
{ id: '$_id', no: '$no' },
'$student'
]
} }
])
My doucments:
[{
"_id":"621c6e805961def3332bcf97",
"title":"monk plus",
"brand":"venture electronics",
"category":"earphones",
"variant":[
{
"price":1100,
"impedance":"16ohm"
},
{
"price":1600,
"impedance":"64ohm"
}],
"salesCount":185,
"buysCount":182,
"viewsCount":250
},
{
"_id":"621c6dab5961def3332bcf92",
"title":"nokia1",
"brand":"nokia",
"category":"mobile phones",
"variant":[
{
"price":10000,
"RAM":"4GB",
"ROM":"32GB"
},
{
"price":15000,
"RAM":"6GB",
"ROM":"64GB"
},
{
"price":20000,
"RAM":"8GB",
"ROM":"128GB"
}],
"salesCount":34,
"buysCount":21,
"viewsCount":80
}]
expected output
[{
_id:621c6e805961def3332bcf97
title:"monk plus"
brand:"venture electronics"
category:"earphones"
salesCount:185
viewsCount:250
variant:[
{
price:1100
impedance:"16ohm"
}]
}]
I have tried this aggregation method
[{
$match: {
'variant.price': {
$gte: 0,$lte: 1100
}
}},
{
$project: {
title: 1,
brand: 1,
category: 1,
salesCount: 1,
viewsCount: 1,
variant: {
$filter: {
input: '$variant',
as: 'variant',
cond: {
$and: [
{
$gte: ['$$variant.price',0]
},
{
$lte: ['$$variant.price',1100]
}
]
}
}
}
}}]
This method returns the expected output, now my question is there any other better approach that return the expected output.Moreover thank you in advance, and as I am new to nosql database so I am curious to learn from the community.Take a note on expected output all properties of particular document must return only the variant array of object I want to filter based on the price.
There's nothing wrong with your aggregation pipeline, and there are other ways to do it. If you just want to return matching documents, with only the first matching array element, here's another way to do it. (The .$ syntax only returns the first match unfortunately.)
db.collection.find({
// matching conditions
"variant.price": {
"$gte": 0,
"$lte": 1100
}
},
{
title: 1,
brand: 1,
category: 1,
salesCount: 1,
viewsCount: 1,
// only return first array element that matched
"variant.$": 1
})
Try it on mongoplayground.net.
Or, if you want to use an aggregation pipeline and return all matching documents in entirety except for the filtered array, you could just "overwrite" the array with the elements you want using "$set" (or its alias "$addFields"). Doing this means you won't need to "$project" anything.
db.collection.aggregate([
{
"$match": {
"variant.price": {
"$gte": 0,
"$lte": 1100
}
}
},
{
"$set": {
"variant": {
"$filter": {
"input": "$variant",
"as": "variant",
"cond": {
"$and": [
{ "$gte": [ "$$variant.price", 0 ] },
{ "$lte": [ "$$variant.price", 1100 ] }
]
}
}
}
}
}
])
Try it on mongoplayground.net.
your solution is good, just make sure to apply your $match and pagination before applying this step for faster queries
I have a collection of components. Simplified, a document looks like this:
{
"_id" : "50c4f4f2-68b5-4153-80db-de8fcf716902",
"name" : "C156",
"posX" : "-136350",
"posY" : "-27350",
"posZ" : "962",
"inspectionIsFailed" : "False"
}
I would now like to calculate three things. The number of all components in the collection, the number of all faulty components "inspectionIsFailed": "True" and then the ratio (number of all faulty components divided by the number of all components).
I know how to get the first two things separately and in a row with one aggregation each.
Number of all components:
db.components.aggregate([
{$group: {_id: null, totalCount: {$sum: 1}}}
]);
Number of all faulty components:
db.components.aggregate([
{$match: {inspectionIsFailed: "True"}},
{$group: {_id: null, failedCount: {$sum: 1}}}
]);
However, I want to calculate the two values in a single pipeline and not separately. Then I could use $divide to calculate the ratio at the end of the pipeline. My desired output should then only contain the ratio:
{ ratio: 0.2 }
My problem with a single pipeline is:
If I try to calculate the total number first, then I can no longer calculate the number of the faulty components. If I first calculate the number of faulty components with $match, I can no longer calculate the total number.
You can try,
$group by null, get totalCount with $sum, and get failedCount on the base of $cond (condition) if inspectionIsFailed id True then return 1 and sum other wise 0
$project to get ratio using $divide
db.collection.aggregate([
{
$group: {
_id: null,
totalCount: { $sum: 1 },
failedCount: {
$sum: {
$cond: [{ $eq: ["$inspectionIsFailed", "True"] }, 1, 0 ]
}
}
}
},
{
$project: {
_id: 0,
ratio: {
$divide: ["$failedCount", "$totalCount"]
}
}
}
])
Playground
As I found out, you can not do it in one pipeline, then you have to use $facet as in this answer explained.
Also I suggest to use boolean for inspectionIsFailed.
db.collection.aggregate([
{
$facet: {
totalCount: [
{
$count: "value"
}
],
pipelineResults: [
{
$match: {
inspectionIsFailed: true
}
},
{
$group: {
_id: "$_id",
failedCount: {
$sum: 1
}
}
}
]
}
}
])
You can test it here.
I recently started working in Mongodb for POC. I have one json collection below
db.ccpsample.insertMany([
{
"ccp_id":1,
"period":601,
"sales":100.00
},
{
"ccp_id":1,
"period":602,
"growth":2.0,
"sales":"NULL" ##sales=100.00*(1+(2.0/100)) -- 100.00 comes from(ccp_id:1 and period=601)
},
{
"ccp_id":1,
"period":603,
"growth":3.0,
"sales":"NULL" ##sales=100.00*(1+(2.0/100))**(1+(3.0/100))-- 100.00 comes from(ccp_id:1 and period=601) 2.0 comes from (ccp_id:2 and period=602)
},
{
"ccp_id":2,
"period":601,
"sales":200.00
},
{
"ccp_id":2,
"period":602,
"growth":2.0,
"sales":"NULL" ##sales=200.00*(1+(2.0/100))
},
{
"ccp_id":2,
"period":603,
"growth":3.0,
"sales":"NULL" ##same like above
}
])
And i need to calculate sales field which has NULL by using above documents with matching conditions of ccp_id should same and period field should be equal to 601. I have added a line to demonstrate calculation of sales field in collection itself above. I tried with $graphlookup but no luck. Can you people kindly help or suggest some way?
You can use below aggregation:
db.ccpsample.aggregate([
{ $sort: { ccp_id: 1, period: 1 } },
{
$group: {
_id: "$ccp_id",
items: { $push: "$$ROOT" },
baseSale: { $first: "$sales" },
growths: { $push: "$growth" }
}
},
{
$unwind: {
path: "$items",
includeArrayIndex: "index"
}
},
{
$project: {
cpp_id: "$items.cpp_id",
period: "$items.period",
growth: "$items.growth",
sales: {
$cond: {
if: { $ne: [ "$items.sales", "NULL" ] },
then: "$items.sales",
else: {
$reduce: {
input: { $slice: [ "$growths", "$index" ] },
initialValue: "$baseSale",
in: { $multiply: [ "$$value", { $add: [1, { $divide: [ "$$this", 100 ] }] } ] }
}
}
}
}
}
}
])
Basically to calculate the value for n-th element you have to know following things:
sales value of first element ($first in $group)
the array of all growths ($push in $group)
the n which indicates how many multiplications you have to perform
To calculate the index you should $push all elements into one array and then use $unwind with includeArrayIndex option which will insert the index of unwinded array to field index.
Last step calculates the cumulative multiplication. It uses $slice with index field to evaluate how many growths should be processed. So there will be one element for 601, two elements for 602 and so on.
Then it's time for $reduce to process that array and perform the multiplications based on your formula: (1 + (growth/100))