I Have 2 collections.
collection 1 model:
{
"_id" : "abcdefgh",
"questionType" : "multiselect",
"question" : "how do you feel",
"options" : [
{
"option" : "Good ",
"additionalTextRequired" : false
},
{
"option" : "Bad",
"additionalTextRequired" : false
}
],
"active" : false,
}
collection 2 model:
{
"_id" : "bhanu",
"someunrelatedfield":"dasf",
"responses" : [
{
"questionId" : "abcdefgh",
"response" : [
"Good"
],
"valid" : true,
"unrelatedfield":"dontprojectthese",
},
{
"questionId" : "someotherid",
"response" : [
"cool"
],
"valid" : true,
}
],
}
I want to get the following result after query,
{
"_id":"bhanu",
"responses":[
{
"question": "how do you feel",
"response": [
"good"
]
"valid":true,
}
]
}
Basically i want to replace "questionId" with "question" in collection 2 and project specified fields.
How can i write query for it?
You need to perform MongoDB aggregation with $lookup operator like this:
db.collection2.aggregate([
{
$lookup: {
from: "collection1",
localField: "responses.questionId",
foreignField: "_id",
as: "tmp"
}
},
{
$addFields: {
responses: {
$map: {
input: "$responses",
as: "response",
in: {
$mergeObjects: [
"$$response",
{
$arrayElemAt: [
{
$filter: {
input: "$tmp",
cond: {
$eq: [
"$$response.questionId",
"$$this._id"
]
}
}
},
0
]
}
]
}
}
}
}
},
{
$unset: [
"responses.questionId"
//put here all fields to be removed
]
}
])
MongoPlayground
Related
I am having mongo collection like below,
{
"_id" : ObjectId("62aeb8301ed12a14a8873df1"),
"Fields" : [
{
"FieldId" : "e8efd0b0-9d10-4584-bb11-5b24f189c03b",
"Value" : [
"test_123"
]
},
{
"FieldId" : "fa6745c2-b259-4a3b-8c6f-19eb78fbbbf5",
"Value" : [
"123"
]
},
{
"FieldId" : "2a1be5d0-8fb6-4b06-a253-55337bfe4bcd",
"Value" : []
},
{
"FieldId" : "eed12747-0923-4290-b09c-5a05107f5609",
"Value" : [
"234234234"
]
},
{
"FieldId" : "fe41d8fb-fa18-4fe5-b047-854403aa4d84",
"Value" : [
"Irrelevan"
]
},
{
"FieldId" : "93e46476-bf2e-44eb-ac73-134403220e9e",
"Value" : [
"test"
]
},
{
"FieldId" : "db434aca-8df3-4caf-bdd7-3ec23252c2c8",
"Value" : [
"2019-06-16T18:30:00.000Z"
]
},
{
"FieldId" : "00df903f-5d59-41c1-a3df-60eeafb77d10",
"Value" : [
"tewt"
]
},
{
"FieldId" : "e97d0386-cd42-6277-1207-e674c3268cec",
"Value" : [
"1"
]
},
{
"FieldId" : "35e55d27-7d2c-467d-8a88-09ad6c9f5631",
"Value" : [
"10"
]
}
]
}
This is all dynamic form fields.
So I want to query and get result like to below object,
{
"_id" : ObjectId("62aeb8301ed12a14a8873df1"),
"e8efd0b0-9d10-4584-bb11-5b24f189c03b": ["test_123"],
"fa6745c2-b259-4a3b-8c6f-19eb78fbbbf5": ["123"],
"2a1be5d0-8fb6-4b06-a253-55337bfe4bcd": [],
"eed12747-0923-4290-b09c-5a05107f5609": ["234234234"],
"fe41d8fb-fa18-4fe5-b047-854403aa4d84": ["Irrelevan"],
"93e46476-bf2e-44eb-ac73-134403220e9e":["test"],
"db434aca-8df3-4caf-bdd7-3ec23252c2c8":["2019-06-16T18:30:00.000Z"],
"00df903f-5d59-41c1-a3df-60eeafb77d10":["1"]
}
I want final output like this combination of fields Fields.FieldID should be key and Fields.Value should be value here.
Please try to help to me to form the object like above.
Thanks in advance!
You can restructure your objects using $arrayToObject, then using that value to as a new root $replaceRoot like so:
db.collection.aggregate([
{
$match: {
// your query here
}
},
{
$project: {
newRoot: {
"$arrayToObject": {
$map: {
input: "$Fields",
in: {
k: "$$this.FieldId",
v: "$$this.Value"
}
}
}
}
}
},
{
"$replaceRoot": {
"newRoot": {
"$mergeObjects": [
"$newRoot",
{
_id: "$_id"
}
]
}
}
}
])
Mongo Playground
I try this and get result like you want
db.collection.aggregate([{
$replaceWith: {
$mergeObjects: [
{
_id: "$_id"
},
{
$arrayToObject: { $zip: {inputs: ["$Fields.FieldId","$Fields.Value"]}}
}
]
}
}])
playground
In here i'm using $lookup to to a left join from other collections, the query works fine but when some records missing values it returns
errmsg : $in requires an array as a second argument, found: null
Heres the querying document structure :
{
"no" : "2020921008981",
"sale" : {
"soldItems" : [
{
"itemId" : "5b55ac7f0550de00210a3b24",
},
{
"itemId" : "5b55ac7f0550de00215584re",
}
],
"bills" : [
{
"billNo" : "2020921053467",
"insurancePlanId" : "160",
},
{
"billNo" : "2020921053467",
"insurancePlanId" : "170",
}
],
"visitIds" : [
5b55ac7f0550de00210a3b24, 5b55ac7f0550de00210a3b24
]
}
}
the query :
db.case.aggregate([
{
$lookup: {
from: "insurance",
let: { ipids: "$sale.bill.insurancePlanId" },
pipeline: [
{
$unwind: "$coveragePlans"
},
{
$match: { $expr: { $in: ["$coveragePlans._id", "$$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"
}
}
])
insurance collection :
{
"_id" : ObjectId("5b55aca20550de00210a6d25"),
"name" : "HIJKL"
"coveragePlans" : [
{
"_id" : "160",
"name" : "UVWZ",
},
{
"_id" : "161",
"name" : "LMNO",
}
]
},
{
"_id" : ObjectId("5b55aca20550de00210a6d25"),
"name" : "WXYZ"
"coveragePlans" : [
{
"_id" : "169",
"name" : "5ABC",
},
{
"_id" : "170",
"name" : "4XYZ",
}
]
}
item collection :
{
"_id" : ObjectId("5b55ac7f0550de00210a3b24"),
"code" : "ABCDE"
},
{
"_id" : ObjectId("5b55ac7f0550de00215584re"),
"code" : "PQRST"
}
How to avoid this and do null checks effectively before pipe-lining into the next stages? Tried with { $match: { "fieldName": { $exists: true, $ne: null } } } but it returns mongo error regarding the format. If its the way to go please mention the stage i should put that.. Thanks in advance
You can use $ifNull operator
let: { ipids: {$ifNull:["$sale.bill.insurancePlanId", [] ]} },
EDIT: To skip empty "$salesOrder.purchaseItems.itemRefId" values
let: { iid: {$filter: {input:"$salesOrder.purchaseItems.itemRefId", cond:{$ne:["$$this", ""]}}} },
You can get around that by not using $in.
It looks like this $map is executed separately for every document in the items collection. If you were to run the map in an $addFields stage, you could used the simple form of lookup to match the added field to _id, which would automagically handle missing, null, and array.
Remove the added field with a $project stage if necessary.
db.case.aggregate([
{$lookup: {
from: "insurance",
let: { ipids: "$sale.bill.insurancePlanId" },
pipeline: [
{$unwind: "$coveragePlans"},
{$match: { $expr: { $in: ["$coveragePlans._id", "$$ipids"] } }},
{$project: { _id: 0, name: 1 }}
],
as: "insurances"
}}
{$addFields:{
matchArray:{$map: {
input: "$$iid",
in: { $toObjectId: "$$this" }
}}
}},
{$lookup: {
from: "item",
localField: "matchArray",
foreignField:"_id",
as: "items"
}},
{$project:{
arrayField: 0
}}
])
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've tried many answers to similar problems using $lookup, $unwind, and $match, but I can't get this to work for my sub-sub-subdocument situation.
I have this collection, Things:
{
"_id" : ObjectId("5a7241f7912cfc256468cb27"),
"name" : "Fortress of Solitude",
"alias" : "fortress_of_solitude",
},
{
"_id" : ObjectId("5a7247ec548c9ad042f579e2"),
"name" : "Batcave",
"alias" : "batcave",
},
{
"_id" : ObjectId("6a7247bc548c9ad042f579e8"),
"name" : "Oz",
"alias" : "oz",
},
and this one-document collection, Venues:
{
"_id" : ObjectId("5b9acabbbf71f39223f8de6e"),
"name" : "The Office",
"floors" : [
{
"name" : "1st Floor",
"places" : [
{
"name" : "Front Entrance",
"alias" : "front_entrance"
}
]
},
{
"name" : "2nd Floor",
"places" : [
{
"name" : "Batcave",
"alias" : "batcave"
},
{
"name" : "Oz",
"alias" : "oz"
}
]
}
]
}
I want to return all the Things, but with the Venue's floors.places.name aggregated with each Thing if it exists if the aliases match between Things and Venues. So, I want to return:
{
"_id" : ObjectId("5a7241f7912cfc256468cb27"),
"name" : "Fortress of Solitude",
"alias" : "fortress_of_solitude",
<-- nothing added here because
<-- it's not found in Venues
},
{
"_id" : ObjectId("5a7247ec548c9ad042f579e2"),
"name" : "Batcave",
"alias" : "batcave",
"floors" : [ <-- this should be
{ <-- returned
"places" : [ <-- because
{ <-- the alias
name" : "Batcave" <-- matches
} <-- in Venues
] <--
} <--
] <--
},
{
"_id" : ObjectId("6a7247bc548c9ad042f579e8"),
"name" : "Oz",
"alias" : "oz",
"floors" : [ <-- this should be
{ <-- returned
"places" : [ <-- because
{ <-- the alias
name" : "Oz" <-- matches
} <-- in Venues
] <--
} <--
] <--
}
I've gotten as far as the following query, but it only returns the entire Venues.floors array as an aggregate onto each Thing, which is way too much extraneous data aggregated. I just want to merge each relevant floor.place sub-subsubdocument from Venues into its corresponding Thing if it exists in Venues.
db.getCollection('things').aggregate([
{$lookup: {from: "venues",localField: "alias",foreignField: "floors.places.alias",as: "matches"}},
{
$replaceRoot: { newRoot: { $mergeObjects: [ { $arrayElemAt: [ "$matches", 0 ] }, "$$ROOT" ] } }
},
{ $project: { matches: 0 } }
])
I'm struggling with existing answers, which seem to change at MongoDB version 3.2, 3.4, 3.6, or 4.2 to include or not include $unwind, $pipeline, and other terms. Can someone explain how to get a sub-sub-subdocument aggregated like this? Thanks!
You can try this :
db.things.aggregate([
{
$lookup:
{
from: "venues",
let: { alias: "$alias" },
pipeline: [
{ $unwind: { path: "$floors", preserveNullAndEmptyArrays: true } },
{ $match: { $expr: { $in: ['$$alias', '$floors.places.alias'] } } },
/** Below stages are only if you've docs like doc 2 in Venues */
{ $addFields: { 'floors.places': { $filter: { input: '$floors.places', cond: { $eq: ['$$this.alias', '$$alias'] } } } } },
{ $group: { _id: '$_id', name: { $first: '$name' }, floors: { $push: '$floors' } } },
{$project : {'floors.places.alias': 1, _id :0}} // Optional
],
as: "matches"
}
}
])
Test : MongoDB-Playground
Since MongoDB v3.6, we may perform uncorrelated sub-queries which gives us more flexibility to join two collections.
Try this:
db.things.aggregate([
{
$lookup: {
from: "venues",
let: {
"alias": "$alias"
},
pipeline: [
{
$unwind: "$floors"
},
{
$project: {
_id: 0,
places: {
$filter: {
input: "$floors.places",
cond: {
$eq: [
"$$alias",
"$$this.alias"
]
}
}
}
}
},
{
$match: {
"places.0": {
$exists: true
}
}
},
{
$unset: "places.name"
}
],
as: "floors"
}
}
])
MongoPlayground
I want to get user's friends and their information. But only wanna join for users where "status" equals to 2.
Here is my object
{
"user_id" : ObjectId("5d2f574b1c27807fd7eb133d"),
"relationship" : [
{
"user_id" : ObjectId("5d2f57661c27807fd7eb133e"),
"status" : 2
},
{
"user_id" : ObjectId("5d2f57c01c27807fd7eb133f"),
"status" : 1
}
]
}
My query
db.getCollection('relationships').aggregate([
{$match: {
user_id: ObjectId("5d2f574b1c27807fd7eb133d")}
},
{ $lookup: {
from: "users",
as: "users",
let: { id: "$_id" },
pipeline: [
{ $match: {
$expr: { $and: [
{ $eq: [ "$relationship.user_id", "$$id" ] },
{ $eq: [ "$relationship.status", 2 ] }
] }
} }
],
} }
])
expected output
{
"user_id" : ObjectId("5d2f574b1c27807fd7eb133d"),
"friends" : [
{
"_id" : ObjectId("5d2f57661c27807fd7eb133e"),
"name" : "Mike"
}
]
}
What's the proper way to do this ?