Upon the aggregate function, the output i have got is of the form :-
> [ { DescriptionArray:
[ 'Des1',
'Des2',
'Des3',
'Des4' ],
PicArray:
[ 'Pic1.jpeg',
'Pic2.jpeg',
'Pic3.jpeg',
'Pic4.jpeg' ] } ]
But, i want the output to be of the form :-
>[ { DescriptionArray:
[
['Des1'],
['Des2'],
['Des3'],
['Des4' ]
],PicArray:
[
['Pic1.jpeg'],
['Pic2.jpeg'],
['Pic3.jpeg'],
['Pic4.jpeg']
] } ]
The aggregate function of mine is as follows:-
>User.aggregate([
{
"$project": {
"_id": 0,
"DescriptionArray": {
"$reduce": {
"input": "$services.description",
"initialValue": [],
"in": {
"$concatArrays": [
"$$this",
"$$value"
]
}
}
},
"PicArray": {
"$reduce": {
"input": "$services.badpic",
"initialValue": [],
"in": {
"$concatArrays": [
"$$this",
"$$value"
]
}
}
}
}
}
])
The schema of my database is as follows:-
> var serviceSchema = new mongoose.Schema({
description:[String],
pic:[String]
})
Is there any way, i can get the output of my desired format?
Related
I want to update many documents based on the condition in MongoDB.
MODEL is the collection which has the document with below information.
"info": [
{
"field1": "String1",
"field2": "String2"
},
{
"field1": "String1",
"field2": "String_2"
}
],
"var": "x"
I need to update all the "String1" value of field1 with "STRING_NEW". I used the below query to update but not working as expected.
db.model.updateMany(
{ "info.field1": { $exists: true } },
[
{ "$set": {
"info": {
"$map": {
"input": "$info.field1",
"in": {
"$cond": [
{ "$eq": ["$$this.field1", "String1"] },
"STRING_NEW",
$$this.field1
]
}
}
}
} }
]
)
Please have a look and suggest if anything is to be modified in the above query.
Solution 1
With the update with aggregation pipeline, you should iterate the object in info array and update the iterated object by merging the current object with new field1 field via $mergeObjects.
db.model.updateMany({
"info.field1": "String1"
},
[
{
"$set": {
"info": {
"$map": {
"input": "$info",
"in": {
"$cond": [
{
"$eq": [
"$$this.field1",
"String1"
]
},
{
$mergeObjects: [
"$$this",
{
"field1": "STRING_NEW"
}
]
},
"$$this"
]
}
}
}
}
}
])
Demo Solution 1 # Mongo Playground
Solution 2
Can also work with $[<identifier>] positional filtered operator and arrayFilters.
db.model.updateMany({
"info.field1": "String1"
},
{
"$set": {
"info.$[info].field1": "STRING_NEW"
}
},
{
arrayFilters: [
{
"info.field1": "String1"
}
]
})
Demo Solution 2 # Mongo Playground
I have the following data:
{
_id: "1"
transitions: [
{
"_id" : "11"
"name" : "Tr1"
"checkLists" : [
{ _id: "111", name: "N1"},
{ _id: "112", name: "N2"}
]
}
]
}
I used the following code to get the name N2 by query of _id:112
db.collection.findOne({ 'transitions.checkLists._id: new ObjectId("112") } }}, { 'transitions.checkLists.$': 1 })
but the result returns back both of them:
{ _id: ObjectId("1"),
transitions:
[ { checkLists:
[ { name: 'N1', _id: ObjectId("111") },
{ name: 'N2', _id: ObjectId("112") } ] } ] }
I would like to find and get only the name N2 by query of _id:112
Expected Result:
{ _id: ObjectId("1"),
transitions:
[ { checkLists:
[ { name: 'N2', _id: ObjectId("112") } ] } ] }
You can do it via the aggregation framework as follow:
db.collection.aggregate([
{
$match: {
"transitions.checkLists._id": "111"
}
},
{
"$addFields": {
"transitions": {
"$map": {
"input": "$transitions",
"as": "t",
"in": {
"$mergeObjects": [
"$$t",
{
"checkLists": {
"$filter": {
"input": "$$t.checkLists",
"as": "c",
"cond": {
$eq: [
"$$c._id",
"111"
]
}
}
}
}
]
}
}
}
}
},
{
"$addFields": {
transitions: {
$filter: {
input: "$transitions",
as: "elem",
cond: {
"$ne": [
"$$elem.checkLists",
[]
]
}
}
}
}
}
])
Explained:
Match the transitions.checkLists._id element in first stage.
Map/mergeobjects with filtered checklists to filter only the needed object from the transitions.checkLists array.
Remove the transitions elements where no checkList exists.
( this need to be done to remove elements for same document where there is no matching _id's )
Playground
I'm trying to match documents without a substring in an array field, in an aggregation pipeline.
I believe I need to add a field and then do a $match on -1, but I'm stuck on $indexOfBytes to find substrings in an array field.
db.collectionName.aggregate([{$addFields:{indexOfA:{$indexOfBytes:['$arrayName.fieldName1.fieldName2','A']}}}])
I get the error:
MongoServerError: PlanExecutor error during aggregation :: caused by :: $indexOfBytes requires a string as the first argument, found: array
collection example:
[
{ arrayName: [ fieldName1: { fieldName2: 'A' } ] },
{ arrayName: [ fieldName1: { fieldName2: 'B' } ] },
{ arrayName: [ fieldName1: { fieldName2: 'C' } ] },
{ arrayName: [ ] }
]
desired result (:
[
{ arrayName: [ fieldName1: { fieldName2: 'B' } ] },
{ arrayName: [ fieldName1: { fieldName2: 'C' } ] },
{ arrayName: [ ] }
]
Maybe something like this:
db.collection.aggregate([
{
$addFields: {
arrayName: {
"$filter": {
"input": "$arrayName",
"as": "a",
"cond": {
$eq: [
{
$indexOfBytes: [
"$$a.fieldName1.fieldName2",
"A"
]
},
-1
]
}
}
}
}
},
{
$match: {
$expr: {
$ne: [
{
$size: "$arrayName"
},
0
]
}
}
}
])
Explained:
$filter arrayName elements not having A in fieldName2
$match only the non-empty arrayName arrays
playground
I have an object schema that looks like this:
{
"_id":"ObjectId(""30t00594537da2r7awe083va"")",
"balances":{
"intraday":[
[
1630939075734,
1899.09
],
[
1630939435939,
1899.32
],
[
1632306730756,
0
],
[
1632306759376,
0
],
[
1632272012916,
1372.22
]
]
}
}
I want to remove all arrays within "balances.intraday" array whose the second element is equal to 0.
so my desired array will looks like this:
{
"_id":"ObjectId(""30t00594537da2r7awe083va"")",
"balances":{
"intraday":[
[
1630939075734,
1899.09
],
[
1630939435939,
1899.32
],
[
1632272012916,
1372.22
]
]
}
}
I tried to use the $pull command but it only removes the index and not the whole array.
======================= Edit =======================
Thanks to Tom Slabbaert the solution is as follows :
db._get_collection().update_many(
{},
[
{
"$set": {
"balances.intraday": {
"$filter": {
"input": "$balances.intraday",
"cond": {
"$ne": [
{
"$arrayElemAt": [
"$$this",
1
]
},
0
]
}
}
}
}
}
])
You should use pipelined updates for this, like so:
db.collection.updateMany(
{},
[
{
$set: {
"balances.intraday": {
$filter: {
input: "$balances.intraday",
cond: {
$ne: [
{
$arrayElemAt: [
"$$this",
1
]
},
0
]
}
}
}
}
}
])
Mongo Playground
I am having the following collection:
{
"price" : [
55800000,
62800000
],
"surface" : [
81.05,
97.4
],
}
I would want to calculate the price/m2. I have tried the following but got the following error: "$divide only supports numeric types, not array and array".
db.entries.aggregate(
[
{ $project: { url: 1, pricePerSquareMeter: { $divide: [ "$price", "$surfaces" ] } } }
]
)
Would you know how to solve this? Ultimately would want to have an array like this:
{
"price" : [
55800000,
62800000
],
"surface" : [
81.05,
97.4
],
"pricePerSquareMeter" : [
688463.91,
644763.86
]
}
Important: The price and surface should also be ordered so that the calculation is valid.
You can use below aggregation
db.collection.aggregate([
{ "$addFields": {
"pricePerSquareMeter": {
"$map": {
"input": { "$range": [0, { "$size": "$price" }] },
"in": {
"$divide": [
{ "$arrayElemAt": ["$price", "$$this"] },
{ "$arrayElemAt": ["$surface", "$$this"] }
]
}
}
}
}}
])
MongoPlayground
You can use below aggregation
db.entries.aggregate([
{ $addFields: {
pricePerSquareMeter: {
$map: {
input: '$price',
as: 'item',
in: {
$divide: [
"$$item",
{ $arrayElemAt: [
"$surface",
{ "$indexOfArray": ["$price", "$$item"] }
]}
]
}
}
},
}}])