In my 'assemblies' collection, each document contains an embedded array of objects called 'partlist':
{
"_id" : ObjectId("0001"),
"pn" : "01",
"title" : "MyAssembly",
"partlist" : [
{
"id" : "",
"pn" : "1234",
"desc" : "myPart1",
},
{
"id" : "",
"pn" : "5678",
"desc" : "myPart2",
}]
}
Within each object, I need to copy the value from 'partlist.pn' into 'partlist.id'. I used:
db.assemblies.aggregate([{$set:{"partlist.id":"$partlist.pn"}}])
hoping to achieve this:
{
"_id" : ObjectId("0001"),
"pn" : "01",
"title" : "MyAssembly",
"partlist" : [
{
"id" : "1234",
"pn" : "1234",
"desc" : "myPart1",
},
{
"id" : "5678",
"pn" : "5678",
"desc" : "myPart2",
}]
}
Instead it returned to 'id' an array of ALL the 'pn' values in 'partlist':
{
"_id" : ObjectId("0001"),
"pn" : "01",
"title" : "MyAssembly",
"partlist" : [
{
"id" : [
"1234",
"5678"
],
"pn" : "1234",
"desc" : "myPart1",
},
{
"id" : [
"1234",
"5678"
],
"pn" : "5678",
"desc" : "myPart2",
}]
}
What is the correct syntax for copying the one value within each object?
What you can do is, you can use $map to modify each elements and mearg the id with the help of $mergeObject
db.collection.aggregate([
{
$addFields: {
"partlist": {
$map: {
input: "$partlist",
in: {
"$mergeObjects": [
"$$this",
{
id: "$$this.pn"
}
]
}
}
}
}
}
])
Working Mongo playground
If the pn does not exist it retrieves initial object.
db.collection.aggregate([
{
$addFields: {
partlist: {
$map: {
input: "$partlist",
as: "p",
in: {
$cond: [
"$$p.pn",
{
$mergeObjects: [
"$$p",
{
"id": "$$p.pn"
}
]
},
"$$p"
]
}
}
}
}
}
])
Playground
Related
i have mongo db collection the follwing structure
{
{
"_id" : ObjectId("63e37afe7a3453d5014c011b"),
"schemaVersion" : NumberInt(1),
"Id" : "ObjectId("63e37afe7a3453d5014c0112")",
"Id1" : "ObjectId("63e37afe7a3453d5014c0113")",
"Id2" : "ObjectId("63e37afe7a3453d5014c0114")",
"collectionName" : "Country",
"List" : [
{
"countryId" : NumberInt(1),
"name" : "Afghanistan",
},{
"countryId" : NumberInt(1),
"name" : "India",
},
{
"countryId" : NumberInt(1),
"name" : "USA",
}
}
i need to match the value with id, id1, id2, collectionName and name in the list to get country id for example if match the below value
"Id" : "ObjectId("63e37afe7a3453d5014c0112")",
"Id1" : "ObjectId("63e37afe7a3453d5014c0113")",
"Id2" : "ObjectId("63e37afe7a3453d5014c0114")",
"collectionName" : "Country",
"name" : "Afghanistan",
i need result
{
"countryId" : 1,
"name" : "Afghanistan",
}
i tried like below
db.country_admin.aggregate([
{ $match: { collectionName: "Country" } },
{ $unwind : '$countryList' },
{ $project : { _id : 0, 'countryList.name' : 1, 'countryList.countryId' : 1 } }
]).pretty()
and i have following output
[
{
"List" : {
"countryId" : 1.0,
"name" : "Afghanistan"
}
},
{
"List" : {
"countryId" : 2.0,
"name" : "india"
}
},
{
"List" : {
"countryId" : 3.0,
"name" : "USA"
}
}]```
You can try using $filter to avoid $unwind like this example:
First $match by your desired condition(s).
Then $filter and get the first element (as "List.name": "Afghanistan" is used into $match stage there will be at least one result).
And output only values you want using $project.
db.collection.aggregate([
{
"$match": {
"Id": ObjectId("63e37afe7a3453d5014c0112"),
"Id1": ObjectId("63e37afe7a3453d5014c0113"),
"Id2": ObjectId("63e37afe7a3453d5014c0114"),
"collectionName": "Country",
"List.name": "Afghanistan",
}
},
{
"$project": {
"country": {
"$arrayElemAt": [
{
"$filter": {
"input": "$List",
"cond": {
"$eq": [
"$$this.name",
"Afghanistan"
]
}
}
},
0
]
}
}
},
{
"$project": {
"_id": 0,
"countryId": "$country.countryId",
"name": "$country.name"
}
}
])
Example here
By the way, using $unwind is also possible and you can check this example
I built up a graph structure using MongoDB. I did some complex queries on this structure already, but I am struggling on selecting a subgraph of a given depth starting from a specific node via the aggregation pipeline.
I already did use the $graphLookup to get all the required nodes, which gives the following result:
{ "_id" : "O_4", "name" : "D", "type" : "Info", "links" : [ { "link" : "L_2", "objectId" : "O_1" }, { "link" : "L_4", "objectId" : "O_3" }, { "link" : "L_10", "objectId" : "O_6" } ] }
{ "_id" : "O_2", "name" : "B", "type" : "Info", "links" : [ { "link" : "L_1", "objectId" : "O_1" }, { "link" : "L_3", "objectId" : "O_3" } ] }
{ "_id" : "O_1", "name" : "A", "type" : "Info", "links" : [ { "link" : "L_1", "objectId" : "O_2" }, { "link" : "L_2", "objectId" : "O_4" } ] }
{ "_id" : "O_3", "name" : "C", "type" : "Info", "links" : [ { "link" : "L_3", "objectId" : "O_2" }, { "link" : "L_4", "objectId" : "O_4" }, { "link" : "L_5", "objectId" : "O_5" }, { "link" : "L_6", "objectId" : "O_7" } ] }
{ "_id" : "O_6", "name" : "F", "type" : "System", "links" : [ { "link" : "L_8", "objectId" : "O_7" }, { "link" : "L_9", "objectId" : "O_5" }, { "link" : "L_10", "objectId" : "O_4" } ] }
But now I want to remove the nested "link" objects (in array "links") where the "objectId" is not present in the above result, i.e. in "O_6" the link "L_8" should be removed, since the node "O_7" is not part of the subgraph.
I already tried playing around with $in, $facet and other stuff to get this problem solved, but it seems like I am unable ...
Maybe, you guys can help out?
Edit:
Just found a solution more or less - $filter does a decent job here:
{
$unwind: "$links"
}, {
$group: {
_id: null,
ids: {
$addToSet: "$_id"
},
links: {
$addToSet: "$links"
}
}
}, {
$project: {
links: {
$filter: {
input: "$links",
as: "link",
cond: {
$in: ["$$link.objectId", "$ids"]
}
}
}
}
}, {
$unwind: "$links"
}, {
$replaceRoot: {
newRoot: "$links"
}
}, {
$group: {
_id: "$link"
}
}
Returns what I needed - the list of Link-IDs:
{ "_id" : "L_1" }
{ "_id" : "L_10" }
{ "_id" : "L_3" }
{ "_id" : "L_2" }
{ "_id" : "L_4" }
I am trying to group a set of documents after an $unwind operation. My documents look like this:
{
"_id" : ObjectId("5cdb5b5acadf5100019da2f4"),
"allowedLocations" : [
{
"type" : "country",
"value" : "world",
"label" : "World"
}
],
"disallowedLocations" : [
{
"type" : "country",
"value" : "CF",
"label" : "Central African Republic"
},
{
"type" : "country",
"value" : "CN",
"label" : "China"
}
],
}
{
"_id" : ObjectId("5cdb5b5acadf5100019da2f4"),
"allowedLocations" : [
{
"type" : "country",
"value" : "US",
"label" : "United States of America"
}
],
"disallowedLocations" : [
{
"type" : "country",
"value" : "CA",
"label" : "Canada"
},
{
"type" : "country",
"value" : "MX",
"label" : "Mexico"
}
],
}
I want to group them by _id and then concatenate the allowedLocations and disallowedLocations arrays into one. The group stage in my pipeline looks like this:
{
"$group" : {
"_id" : "$_id",
"allowedLocations" : {
"$push" : "$allowedLocations"
},
"disallowedLocations" : {
"$push" : "disallowedLocations"
}
}
}
The problem is, the result I get is not a document with both arrays concatenated, but an array of arrays, each element of the array being the array of each document:
{
"_id" : ObjectId("5cdb5b5acadf5100019da2f4"),
"allowedLocations" : [
[
{
"type" : "country",
"value" : "US",
"label" : "United States of America"
}
],
[
{
"type" : "country",
"value" : "world",
"label" : "World"
}
],
],
"disallowedLocations" : [
[
{
"type" : "country",
"value" : "CF",
"label" : "Central African Republic"
},
{
"type" : "country",
"value" : "CN",
"label" : "China"
}
],
[
{
"type" : "country",
"value" : "CA",
"label" : "Canada"
},
{
"type" : "country",
"value" : "MX",
"label" : "Mexico"
}
]
}
}
Is there a way to produce a flat array with only objects as elements? I also tried with $concatArrays before the push but that creates more arrays inside the arrays.
Two solutions here. You can either run $unwind on both arrays to get single allowed and disallowed location per document and then run your $group stage:
db.col.aggregate([
{
$unwind: "$allowedLocations"
},
{
$unwind: "$disallowedLocations"
},
{
"$group" : {
"_id" : "$_id",
"allowedLocations" : {
"$addToSet" : "$allowedLocations"
},
"disallowedLocations" : {
"$addToSet" : "$disallowedLocations"
}
}
}
])
or you can run your $group first and then use $reduce to flatten allowedLocations and disallowedLocations:
db.col.aggregate([
{
"$group" : {
"_id" : "$_id",
"allowedLocations" : {
"$push" : "$allowedLocations"
},
"disallowedLocations" : {
"$push" : "$disallowedLocations"
}
}
},
{
$project: {
_id: 1,
allowedLocations: {
$reduce: {
input: "$allowedLocations",
initialValue: [],
in: { $concatArrays: [ "$$value", "$$this" ] }
}
},
disallowedLocations: {
$reduce: {
input: "$disallowedLocations",
initialValue: [],
in: { $concatArrays: [ "$$value", "$$this" ] }
}
}
}
}
])
Started with mongoDB syntax and use in project.
I am looking for a solution where I can combine more than two collections with couple of condition to create a view.
Here is my collection Range
/* 1 */
{
"_id" : ObjectId("1"),
"range" : {
"start" : "00"
},
"products" : [
{
"id" : "01",
"name" : "FirstProduct",
"type" : "First Type"
},
{
"id" : "02",
"name" : "Second Product",
"type" : "Second Type"
},
{
"id" : "03",
"name" : "Third Product",
"type" : "Third Type"
},
]
}
/* 2 */
{
"_id" : ObjectId("2"),
"range" : {
"start" : "100",
},
"products" : [
{
"id" : "01",
"name" : "First Product",
"type" : "First Type"
},
{
"id" : "02",
"name" : "Second Product",
"type" : "Second Type"
}
]
}
/* 3 */
{
"_id" : ObjectId("3"),
"range" : {
"start" : "500",
},
"products" : [
{
"id" : "01",
"name" : "First Product",
"type" : "First Type"
},
{
"id" : "02",
"name" : "Second Product",
"type" : "Second Type"
}
]
}
Second Collection. Stock
/* 1 */
{
"_id" : ObjectId("1"),
"range" : {
"start" : "00"
},
"products" : [
{
"id" : "01",
"expired" : false,
"returned" : false
},
{
"id" : "02",
"expired" : false,
"returned" : false
}
]
}
/* 2 */
{
"_id" : ObjectId("02"),
"range" : {
"start" : "100"
},
"products" : [
{
"id" : "01",
"expired" : true,
"returned" : true
},
{
"id" : "02",
"expired" : true,
"returned" : true
}
{
"id" : "03",
"expired" : true,
"returned" : true
}
]
}
Now want to have a view with combine result from above two collection above.
For each range document in Range collections
if Range.range.start = Stock.range.start
if Range.products.id = Stock.products.id
copy "expired" and "returned" field from Stock for that product and
add to Range.product
end if
end if
Return Range
So final result will something like below.
/* 1 */
{
"_id" : ObjectId("1"),
"range" : {
"start" : "00"
},
"products" : [
{
"id" : "01",
"name" : "FirstProduct",
"type" : "First Type"
"expired" : false,
"returned" : false
},
{
"id" : "02",
"name" : "Second Product",
"type" : "Second Type"
"expired" : false,
"returned" : false
}
]
}
/* 2 */
{
"_id" : ObjectId("2"),
"range" : {
"start" : "100",
},
"products" : [
{
"id" : "01",
"name" : "First Product",
"type" : "First Type",
"expired" : true,
"returned" : true
},
{
"id" : "02",
"name" : "Second Product",
"type" : "Second Type",
"expired" : true,
"returned" : true
}
]
}
/* 3 */
{
"_id" : ObjectId("3"),
"range" : {
"start" : "500",
},
"products" : [
{
"id" : "01",
"name" : "First Product",
"type" : "First Type"
},
{
"id" : "02",
"name" : "Second Product",
"type" : "Second Type"
}
]
}
I started with aggregate pipeline stages with fail to get right queries.
if anyone can help with right syntax and proper aggregate function.
Thanks in advance.
You need $lookup to merge the data from both collections but then you have to use $unwind to be able to match corresponding documents by product.id. In the last step you can use $group to get back an array:
db.Range.aggregate([
{
$lookup: {
from: "Stock",
localField: "range.start",
foreignField: "range.start",
as: "stock"
}
},
{
$unwind: "$stock"
},
{
$unwind: "$products"
},
{
$unwind: "$stock.products"
},
{
$match: { $expr: { $eq: [ "$products.id", "$stock.products.id" ] } }
},
{
$group: {
_id: "$_id",
"range": { $first: "$range" },
products: {
$push: {
id: "$products.id",
name: "$products.name",
type: "$products.type",
expired: "$stock.products.expired",
returned: "$stock.products.returned"
}
}
}
}
])
EDIT: Alternative solution which operates directly on arrays using $map and $filter below. The drawback is that the code is less readable but the good part is that it should return documents when there's no match and you should get better performance using this approach
db.Range.aggregate([
{
$lookup: {
from: "Stock",
localField: "range.start",
foreignField: "range.start",
as: "stock"
}
},
{
$unwind: "$stock"
},
{
$addFields: {
products: {
$map: {
input: "$products",
as: "p",
in: {
$let: {
vars: {
stockItem: {
$arrayElemAt: [
{ $filter: { input: "$stock.products", cond: { $eq: [ "$$p.id", "$$this.id" ] } } }, 0
]
}
},
in: {
$cond: [
{ $eq: [ "$$stockItem", undefined ] },
"$$p",
{
id: "$$p.id",
name: "$$p.name",
type: "$$p.type",
expired: "$$stockItem.expired",
returned: "$$stockItem.returned",
}
]
}
}
}
}
}
}
},
{
$project: {
stock: 0
}
}
])
Here i have two document ,in this documents childNodes array ID is duplicate means , i want to take the userID and pedagogyID of the record,as per my documents second document under childNodes array 798 is coming duplicate, so i want to take the records
Documents
{
"userID" : "A",
"pedagogyID" : "100",
"summary" : {
"LearnProgress" : {
"childNodes" : [
{
"ID" : "123",
"status" : "in-progress"
},
{
"ID" : "456",
"status" : null
},
{
"ID" : "333",
"status" : null
}
],
}
}
}
{
"userID" : "B",
"pedagogyID" : "200",
"summary" : {
"LearnProgress" : {
"childNodes" : [
{
"ID" : "789",
"status" : "in-progress"
},
{
"ID" : "1010",
"status" : null
},
{
"ID" : "789",
"status" : null
}
],
}
}
}
Expected Output
{
"userID" : "B",
"pedagogyID" : "200",
}
MY Code
db.collectionname.aggregate(
[
{"$unwind":"$summary.LearnProgress.childNodes"},
{"$group":{
"_id":{"_id":"$_id","ID":"$summary.LearnProgress.childNodes.ID"},
"userID":{"$first":"$userID"},
"pedagogyID":{"$first":"$pedagogyID"},
"count":{"$sum":1}
}},
{"$match":{"count":{"$gt":1}}},
{"$group":{"_id":{"userID":"$userID","pedagogyID":"$pedagogyID"}}},
{"$replaceRoot":{"newRoot":"$_id"}}
],
{ allowDiskUse:true }
)
You can use below aggregation.
db.colname.aggregate([
{"$unwind":"$summary.LearnProgress.childNodes"},
{"$group":{
"_id":{"_id":"$_id","ID":"$summary.LearnProgress.childNodes.ID"},
"userID":{"$first":"$userID"},
"pedagogyID":{"$first":"$pedagogyID"},
"count":{"$sum":1}
}},
{"$match":{"count":{"$gt":1}}},
{"$group":{"_id":{"userID":"$userID","pedagogyID":"$pedagogyID"}}},
{"$replaceRoot":{"newRoot":"$_id"}}
],{"allowDiskUse":true})
db.collectionname.aggregate(
// Pipeline
[
// Stage 1
{
$unwind: {
path : "$summary.LearnProgress.childNodes",
}
},
// Stage 2
{
$group: {
_id:'$summary.LearnProgress.childNodes.ID',
count:{$sum:1},
pedagogyID:{$first:'$pedagogyID'},
userID:{$first:'$userID'}
}
},
// Stage 3
{
$match: {
count:{$gt:1}
}
},
// Stage 4
{
$project: {
userID:1,
pedagogyID:1,
_id:0
}
},
]
);