Lets say I have a mongodb document
{
"id" : 1,
"types" : ["online" ,"offline"],
"applications" : [ ["online", "online"], ["offline"] ]
}
I would like to transformed into
{
"id" : 1,
"types" : [
{
"type" : "online",
"count" : 2,
"applications" : [ "online", "online"]
},
{
"type" : "offline",
"count" : 1,
"applications" : [ "offline" ]
}
]
}
here types and applications arrays can be of any size.
You can do that in two steps, use $map with $filter to match type with applications and then run $reduce to get count:
db.collection.aggregate([
{
$project: {
id: 1,
types: {
$map: {
input: "$types",
as: "type",
in: {
type: "$$type",
applications: {
$filter: {
input: "$applications",
as: "application",
cond: {
$allElementsTrue: {
$map: { input: "$$application", in: { $eq: [ "$$this", "$$type" ] } }
}
}
}
}
}
}
}
}
},
{
$addFields: {
types: {
$map: {
input: "$types",
in: {
$mergeObjects: [
"$$this",
{
count: {
$reduce: {
input: "$$this.applications",
initialValue: 0,
in: { $add: [ "$$value", { $size: "$$this" } ] }
}
}
}
]
}
}
}
}
}
])
You can decide whether it's better to use $allElementsTrue or $anyElementTrue when building your filtering criteria.
Mongo Playground
Related
I have a collection called countries:
{
"_id" : "123456",
"enabled" : true,
"entity" : {
"name" : [
{
"locale" : "en",
"value" : "Lithuania"
},
{
"locale" : "de",
"value" : "Litauen"
}
]
}
}
I like to return only the ObjectId and the value when the locale is "en".
{"_id":"123456", "value":"Lithuania"}
Ideally renaming value to country for:
{"_id":"123456", "country":"Lithuania"}
Using a projection like:
db.countries.aggregate([
{$project:
{country: {$arrayElemAt:["$entity.name",0]}}
}
])
returns almost the desired results:
{"_id" : "1234565", "country" : { "locale" : "en", "value" : "Lithuania" } }
This this one:
db.collection.aggregate([
{
$set: {
country: {
$filter: {
input: "$entity.name",
cond: { $eq: [ "$this.locale", "en" ] }
}
}
}
},
{ $project: { country: { $first: "$country.value" } } },
])
See Mongo playground
You can try,
$reduce to iterate loop of entity.name array, $cond check locale is "en" then return value
db.collection.aggregate([
{
$project: {
country: {
$reduce: {
input: "$entity.name",
initialValue: "",
in: {
$cond: [
{ $eq: ["$$this.locale", "en"] },
"$$this.value",
"$$value"
]
}
}
}
}
}
])
Playground
I should have specified the MongoDB Version. Server is running 3.6.20. For that the following solution works:
db.countries.aggregate([
{
$addFields: {
country: {
$filter: {
input: "$entity.name",
cond: { $eq: [ "$$this.locale", "en" ] }
}
}
}
},
{ $project: { country: { $arrayElemAt: [["$country.value"],0] } } },
])
I would like to concat int array field values inside an array of objects into one string field after dividing them (by 10).
Heres the existing document format:
{
"no" : "2020921008981",
"date" : ISODate("2020-04-01T05:19:02.263+0000"),
"sale" : {
"soldItems" : [
{
"itemRefId" : "5b55ac7f0550de00210a3b24",
"soldPrice" : NumberInt(800),
},
{
"itemRefId" : "5b55ac7f0550de00210a3b25",
"soldPrice" : NumberInt(1000),
}
]
}
}
Expected result :
{
"no" : "2020921008981",
"date" : ISODate("2020-04-01T05:19:02.263+0000"),
"priceList" : "8.0 \n 10.0"
}
The attempt with $reduce :
priceList: {
$reduce: {
input: "$sale.soldItems.soldPrice",
initialValue: "",
in: {
$cond: [ { "$eq": [ { $toString: { $divide: [ "$$value", 10 ] } }, "" ] }, "$$this", { $concat: [ { $toString: { $divide: [ "$$value", 10 ] } }, "\n", "$$this" ] } ]
}
}
}
But end up getting "errmsg" : "$divide only supports numeric types, not string and double" error. Any idea would be appreciated.
db.case.aggregate([
{
$set: {
priceList: {
$reduce: {
input: {
$map: {
input: "$sale.soldItems.soldPrice",
in: { $toString: { $divide: ["$$this", 10] } }
}
},
initialValue: "",
in: { $concat: ["$$value", "$$this", " \n "] }
}
}
}
},
{
$project: {
_id: 0,
no: 1,
date: 1,
priceList: 1
}
}
])
Try the following aggregation query, where the idea is to:
First divide the field soldPrice by 10 or required divisor using $divide
Convert it into string and concat using $toString and $concat
the appender \n gets appended after each reduce op,remove that from the end using $rtrim
create the new field using $addFields
Query:
db.collection.aggregate([
{
$addFields: {
"itemPriceList": {
$rtrim: {
input: {
$reduce: {
input: "$salesOrder.purchaseItems",
initialValue: "",
in: {
$concat: [
"$$value",
{
$toString: {
$divide: [
"$$this.soldPrice",
10
]
}
},
"\n"
]
}
}
},
chars: "\n"
}
}
}
}
]);
Result:
[
{
"_id": ObjectId("5a934e000102030405000000"),
"caseNumber": "2020921008981",
"itemPriceList": "80\n100",
"salesOrder": {
"purchaseItems": [
{
"itemRefId": "5b55ac7f0550de00210a3b24",
"soldPrice": 800
},
{
"itemRefId": "5b55ac7f0550de00210a3b25",
"soldPrice": 1000
}
]
},
"startTime": ISODate("2016-05-18T16:00:00Z")
}
]
Plaground Test Link
I have a collection myCollection with array of members :
{
name : String,
members: [{status : Number, memberId : {type: Schema.Types.ObjectId, ref: 'members'}]
}
and i have this data
"_id" : ObjectId("5e83791eb49ab07a48e0282b")
"members" : [
{
"status" : 1,
"_id" : ObjectId("5e83791eb49ab07a48e0282c"),
"memberId" : ObjectId("5e7dbf5b257e6b18a62f2da9")
},
{
"status" : 2,
"_id" : ObjectId("5e837944b49ab07a48e0282d"),
"memberId" : ObjectId("5e7de2dbe027f43adf678db8")
}
],
I want to check by aggregate query if member 5e7dbf5b257e6b18a62f2da9 exists with status 1 but it didn't return true
db.getCollection('myCollection').aggregate([
{$match: {_id: ObjectId("5e83791eb49ab07a48e0282b")}},
{
$project: {
isMember: {
$cond: [
{ $and: [ {$in: [ObjectId("5e7dbf5b257e6b18a62f2da9"), '$members.memberId']}, {$eq: ['$members.status', 1]} ] },
// if
true, // then
false // else
]
}
}
}
])
Thank you for your responses.
If you want to get just true/false you can shortcut like this:
db.collection.aggregate([
{ $match: { _id: ObjectId("5e83791eb49ab07a48e0282b") } },
{
$project: {
isMember: {
$map: {
input: "$members",
in: {
$and: [
{ $eq: [ObjectId("5e7dbf5b257e6b18a62f2da9"), '$$this.memberId'] },
{ $eq: [1, '$$this.status'] }
]
}
}
}
}
},
{ $set: { isMember: { $anyElementTrue: "$isMember" } } }
])
A different style would be this:
db.collection.aggregate([
{ $match: { _id: ObjectId("5e83791eb49ab07a48e0282b") } },
{
$project: {
isMember: {
$map: {
input: "$members",
in: {
$eq: [
{ memberId: ("5e7dbf5b257e6b18a62f2da9"), status: 1 },
{ memberId: "$$this.memberId", status: "$$this.status" }
]
}
}
}
}
},
{ $set: { isMember: { $anyElementTrue: "$isMember" } } }
])
Trying to do $lookup s for local array fields which is inside an object.
Querying case collection :
{
"no" : "2020921008981",
"sale" : {
"soldItems" : [
{
"itemId" : "5b55ac7f0550de00210a3b24",
},
{
"itemId" : "5b55ac7f0550de00215584re",
}
],
"bills" : [
{
"billNo" : "2020921053467",
"insurancePlanId" : "160",
},
{
"billNo" : "2020921053467",
"insurancePlanId" : "170",
}
]
}
}
Item collection :
{
"_id" : ObjectId("5b55ac7f0550de00210a3b24"),
"code" : "ABCDE"
},
{
"_id" : ObjectId("5b55ac7f0550de00215584re"),
"code" : "PQRST"
}
Insurance collection :
{
"_id" : ObjectId("5b55aca20550de00210a6d25"),
"name" : "HIJKL"
"plans" : [
{
"_id" : "160",
"name" : "UVWZ",
},
{
"_id" : "161",
"name" : "LMNO",
}
]
},
{
"_id" : ObjectId("5b55aca20550de00210a6d25"),
"name" : "WXYZ"
"coveragePlans" : [
{
"_id" : "169",
"name" : "5ABC",
},
{
"_id" : "170",
"name" : "4XYZ",
}
]
}
Desired output :
{
"no" : "2020921008981",
"sale" : {}
"insurances" : "HIJKL \n WXYZ",
"items" : [
{
"_id" : ObjectId("5b55ac7f0550de00210a3b24"),
"code" : "ABCDE"
},
{
"_id" : ObjectId("5b55ac7f0550de00215584re"),
"code" : "PQRST"
}
]
}
The attempt to lookup using the local itemRefId field from the item collection. And to lookup using the local insurancePlanId from the insurance collection and then $reduce the returning array into the desired format for the insurances field:
{
$lookup:
{
from: "item",
let: { iid: "$sale.soldItems.itemId" },
pipeline: [
{
$match: {
$expr: {
$in: ["$_id", {
$map: {
input: "$$iid",
in: { $_id: "$$this" }
}
}
]
}
}
}
],
as: "items"
}
},
{
$lookup:
{
from: "insurance",
let: { iid: "$sale.insurances.insurancePlanId" },
pipeline: [
{
$match: {
$expr: {
$in: ["$insurance.plans._id", {
$map: {
input: "$$iid",
in: { $toObjectId: "$$this" }
}
}
]
}
}
}
],
as: "insurancesList"
}
},
{
$addFields: {
insurances: {
$reduce: {
input: "$insurancesList.name",
initialValue: "",
in: {
$cond: [ { "$eq": [ "$$value", "" ] }, "$$this", { $concat: [ "$$value", "\n", "$$this" ] } ]
}
}
}
}
}
This attempt returns a mongodb error. Any help to get the desired output would be appreciated.
db.case.aggregate([
{
$lookup: {
from: "insurance",
let: { ipids: "$salesOrder.invoices.insurancePlanId" },
pipeline: [
{
$unwind: "$coveragePlans"
},
{
$match: { $expr: { $in: ["$coveragePlans._id", "$$ipids"] } }
},
{
$project: { _id: 0, name: 1 }
}
],
as: "insurances"
}
},
{
$lookup: {
from: "item",
let: { iid: "$salesOrder.purchaseItems.itemRefId" },
pipeline: [
{
$match: {
$expr: {
$in: ["$_id", {
$map: {
input: "$$iid",
in: { $toObjectId: "$$this" }
}
}
]
}
}
}
],
as: "items"
}
},
{
$project: {
_id: 0,
caseNumber: 1,
insurances: {
$reduce: {
input: "$insurances",
initialValue: "",
in: { $concat: ["$$value", "$$this.name", " \n "] }
}
},
items: 1
}
}
])
I want to select the $user_a_seen_at field if $user_a_id == socket.user_id otherwise select the $user_b_seen_at field. But my query isn't working.
$gt: ["$$this.created_at", IF CONDITION TO SELECT A FIELD ]
$project: {
unread_messages: {
$size: {
$filter: {
input: "$messages",
cond: {
$and: [
{ $eq: ["$$this.to_id", socket.user_id] },
{
$gt: [
"$$this.created_at", {
if: { $eq: ["$user_a_id", socket.user_id] },
then: "$user_a_seen_at",
else: "$user_b_seen_at"
}
]
}
]
}
}
}
}
}
Sample data
{
"_id" : ObjectId("5e4c57649fad2e2cac9f8cd5"),
"user_a_id" : 1,
"user_b_id" : 2,
"user_a_seen_at" : ISODate("2020-02-18T21:30:12.418Z"),
"user_b_seen_at" : ISODate("2020-02-18T15:30:12.418Z"),
"messages" : [
{
"text" : "Hello",
"_id" : ObjectId("5e4c57649fad2e2cac9f8cd4"),
"from_id" : 1,
"to_id" : 2,
"created_at" : ISODate("2020-02-18T21:30:12.409Z")
}
],
"created_at" : ISODate("2020-02-18T21:30:12.418Z"),
"last_activity" : ISODate("2020-02-18T21:30:12.418Z"),
"__v" : 0
}
You need to use $cond operator to evaluate a boolean expression to return one of the two specified return expressions
{ $cond: { if: <boolean-expression>, then: <true-case>, else: <false-case> } }
//or simplified
{ $cond: [ <boolean-expression>, <true-case>, <false-case> ] }
db.collection.aggregate([
{
$project: {
unread_messages: {
$size: {
$filter: {
input: "$messages",
cond: {
$and: [
{
$eq: [
"$$this.to_id",
socket.user_id
]
},
{
$gt: [
"$$this.created_at",
{
$cond: [
{
$eq: [
"$user_a_id",
socket.user_id
]
},
"$user_a_seen_at",
"$user_b_seen_at"
]
}
]
}
]
}
}
}
}
}
}
])
MongoPlayground