Here is the collection:
db.employees.insertMany([
{
"data": {
"category": [
{
"name": "HELLO",
"subcategory": [
"EDUCATION",
"ART",
]
},
{
"name": "HELLO",
"subcategory": [
"GG",
"ART",
]
},
{
"name": "HELLO",
"subcategory": [
"EDUCATION",
"SHORE",
]
}
]
}
},
{
"data": {
"category": [
{
"name": "HELLO",
"subcategory": [
"EDUCATION",
"HELLO",
]
}
]
}
},
{
"data": {
"category": [
{
"name": "HELLO",
"subcategory": [
"GG",
"ART",
]
}
]
}
}
]);
What I want is to locate the elements in 'category' with a 'subcategory' that contains 'EDUCATION' and replace 'EDUCATION' with another string, let's say 'SPORTS'.
I tried a couple of commands but nothing really did the job:
db.employees.updateMany({
"data.category.subcategory": "EDUCATION"
},
{
"$set": {
"data.category.$": {
"subcategory": "SPORTS"
}
}
})
What I saw is that it doesn't update the element by replacing it and it doesn't replace every element that meets the criteria.
Think that MongoDB Update with Aggregation Pipeline fulfills your scenario.
$set - Set data.category value.
1.1. $map - Iterate each element in data.category and return an array.
1.1.1. $mergeObjects - Merge the current document with the document with subcategory field from 1.1.1.1.
1.1.1.1 $map - Iterate each value from the subcategory array. With $cond to replace the word EDUCATION with SPORTS if fulfilled, else use existing value ($$this).
db.employees.updateMany({
"data.category.subcategory": "EDUCATION"
},
[
{
"$set": {
"data.category": {
$map: {
input: "$data.category",
in: {
$mergeObjects: [
"$$this",
{
subcategory: {
$map: {
input: "$$this.subcategory",
in: {
$cond: {
if: {
$eq: [
"$$this",
"EDUCATION"
]
},
then: "SPORTS",
else: "$$this"
}
}
}
}
}
]
}
}
}
}
}
]
Sample Mongo Playground
Here's another way to do it using "arrayFilters".
db.collection.update({
"data.category.subcategory": "EDUCATION"
},
{
"$set": {
"data.category.$[].subcategory.$[elem]": "SPORTS"
}
},
{
"arrayFilters": [
{ "elem": "EDUCATION" }
],
"multi": true
})
Try it on mongoplayground.net.
Related
In my example project, I have employees under manager. Db schema is like this;
{
"employees": [
{
"name": "Adam",
"_id": "5ea36b27d7ae560845afb88e",
"bananas": "allowed"
},
{
"name": "Smith",
"_id": "5ea36b27d7ae560845afb88f",
"bananas": "not-allowed"
},
{
"name": "John",
"_id": "5ea36b27d7ae560845afb88g",
"bananas": "not-allowed"
},
{
"name": "Patrick",
"_id": "5ea36b27d7ae560845afb88h",
"bananas": "allowed"
}
]
}
In this case Adam is allowed to eat bananas and Smith is not. If I have to give the permission of eating bananas from Adam to Smith I need to perform update operation twice like this:
db.managers.update(
{ 'employees.name': 'Adam' },
{ $set: { 'employees.$.bananas': 'not-allowed' } }
);
and
db.managers.update(
{ 'employees.name': 'Smith' },
{ $set: { 'employees.$.bananas': 'allowed' } }
);
Is it possible to handle this in a single query?
You can use $map and $cond to perform conditional update to the array entries depending on the name of the employee. A $switch is used for potential extension of cases.
db.collection.update({},
[
{
"$set": {
"employees": {
"$map": {
"input": "$employees",
"as": "e",
"in": {
"$switch": {
"branches": [
{
"case": {
$eq: [
"$$e.name",
"Adam"
]
},
"then": {
"$mergeObjects": [
"$$e",
{
"bananas": "not-allowed"
}
]
}
},
{
"case": {
$eq: [
"$$e.name",
"Smith"
]
},
"then": {
"$mergeObjects": [
"$$e",
{
"bananas": "allowed"
}
]
}
}
],
default: "$$e"
}
}
}
}
}
}
])
Mongo Playground
db.managers.update(
{
$or: [
{"employees.name": "Adam"},
{"employees.name": "Smith"}
]
},
{
$set: {
"employees.$[e].bananas": {
$cond: [{ $eq: ["$e.name", "Adam"] }, "not-allowed", "allowed"]
}
}
},
{
arrayFilters: [{ "e.name": { $in: ["Adam", "Smith"] } }]
}
)
This question is slightly different from others since I need to get the whole documents and not just specific fields.
I need to filter documents(all of the document, not just specific fields), according to the last elements value of a nested array. (doc.array[i].innerArray[innerArray.length - 1].desiredField)
Documents are looking like this:
[
{
"_id": 0,
"matches": [
{
"name": "match 1",
"ids": [
{
"innerName": "1234"
},
{
"innerName": "3"
}
]
}
]
},
{
"_id": 1,
"matches": [
{
"name": "match 5",
"ids": [
{
"innerName": "123"
},
{
"innerName": "1"
}
]
},
{
"name": "match 5",
"ids": [
{
"innerName": "1"
},
{
"innerName": "1234"
},
]
},
]
}
]
So if we filter according to innerName = '1234', this is the result:
{
"_id": 1,
"matches": [
{
"name": "match 5",
"ids": [
{
"innerName": "123"
},
{
"innerName": "1"
}
]
},
{
"name": "match 5",
"ids": [
{
"innerName": "1"
},
{
"innerName": "1234"
},
]
}
One option is:
db.collection.find({
$expr: {
$in: [
"1234",
{$reduce: {
input: "$matches",
initialValue: [],
in: {$concatArrays: ["$$value", [{$last: "$$this.ids.innerName"}]]}
}
}
]
}
})
See how it works on the playground example
Another option:
db.collection.aggregate([
{
$match: {
$expr: {
$gt: [
{
$size: {
$filter: {
input: "$matches",
cond: {
$in: [
{
$last: "$$this.ids.innerName"
},
[
"1234"
]
]
}
}
}
},
0
]
}
}
}
])
Explained:
Match only documents where size of array is >0 for those who has "1234" in last nested array element.
Playground:
Let's say I have a sample object as below
[
{
"status": "ACTIVE",
"person": [
{
"name": "Jim",
"age": "2",
"qualification": [
{
"type": "education",
"degree": {
"name": "bachelor",
"year": "2022"
}
},
{
"type": "certification",
"degree": {
"name": "aws",
"year": "2021"
}
}
]
}
]
}
]
Now, I need to add a field "score" only when the qualification.type == bachelor
This is the query I tried but could not get the proper result. Not sure what mistake I am doing. Any help is highly appreciated. Thank you in advance.
db.collection.aggregate([
{
$addFields: {
"person.qualification.score": {
$reduce: {
input: "$person.qualification",
initialValue: "",
in: {
$cond: [
{
"$eq": [
"$$this.type",
"bachelor"
]
},
"80",
"$$REMOVE"
]
}
}
}
}
}
])
$set - Set person array field.
1.1. $map - Iterate person array and return a new array.
1.1.1. $mergeObjects - Merge current iterate (person) document and the document with qualification.
1.1.1.1. $map - Iterate the qualification array and return a new array.
1.1.1.1.1. $cond - Match type of current iterate qualification document. If true, merge current iterate qualification document and the document with score field via $mergeObjects. Else remain the existing document.
db.collection.aggregate([
{
$set: {
person: {
$map: {
input: "$person",
as: "p",
in: {
$mergeObjects: [
"$$p",
{
qualification: {
$map: {
input: "$$p.qualification",
in: {
$cond: {
if: {
$eq: [
"$$this.type",
"education"
]
},
then: {
$mergeObjects: [
"$$this",
{
score: "80"
}
]
},
else: "$$this"
}
}
}
}
}
]
}
}
}
}
}
])
Sample Mongo Playground
I have a documents like below. I want to retrieve all documents whose address.city == "newyork" and address.id == active.
[
{
"name": "star1",
"active": 1,
"address": [
{
"id": 1,
"city": "newyork"
},
{
"id": 2,
"city": "sydney"
}
]
},
{
"name": "star2",
"active": 2,
"address": [
{
"id": 1,
"city": "newyork"
},
{
"id": 2,
"city": "london"
}
]
}
]
I have written below query and it Partially works, But It is not returning complete document. I can't use unwind. Do we have any solution without using "unwind". Is it possible to solve a problem only with $match
db.collection.aggregate([
{
$unwind: "$address"
},
{
$match: {
$expr: {
$eq: [
"$active",
"$address.id"
]
},
"address.city": "newyork"
}
}
])
Maybe something like this:
db.collection.aggregate([
{
"$addFields": {
"address": {
"$filter": {
"input": "$address",
"as": "a",
"cond": {
$and: [
{
$eq: [
"$$a.id",
"$active"
]
},
{
$eq: [
"$$a.city",
"newyork"
]
}
]
}
}
}
}
},
{
$match: {
address: {
$ne: []
}
}
}
])
Explained:
Use addFields/filter to match only matching documents in the array.
Remove the documents with empty address from the array for the cases where no subdocuments is found.
Playground
In case you need to match the whole document containing at least one entry having {address.id==active and address.city==newyork } here is an option:
db.collection.aggregate([
{
$match: {
$expr: {
"$in": [
{
id: "$active",
city: "newyork"
},
"$address"
]
}
}
}
])
Explained:
Match only documents having at least one object in address array with id==$active and city=="newyork"
Playground
In case we expect different order inside the address objects , the more correct option is as follow:
db.collection.aggregate([
{
$match: {
$expr: {
$or: [
{
"$in": [
{
id: "$active",
city: "newyork"
},
"$address"
]
},
{
"$in": [
{
city: "newyork",
id: "$active"
},
"$address"
]
}
]
}
}
}
])
Explained:
Match only documents having at least one object in array with { id==$active and city=="newyork" } or { city=="newyork" and id==$active }
Playground 2
I have this portion of collections:
[{
"_id": ObjectId("604f3ae3194f2135b0ade569"),
"parameters": [
{
"_id": ObjectId("602b7455f4b4bf5b41662ec1"),
"name": "Purpose",
"options": [
{
"id": ObjectId("602b764ff4b4bf5b41662ec2"),
"name": "debug",
"sel": true
},
{
"id": ObjectId("602b767df4b4bf5b41662ec3"),
"name": "performance",
"sel": false
},
{
"id": ObjectId("602b764ff4b4bf5b41662ec4"),
"name": "security",
"sel": true
},
{
"id": ObjectId("602b767df4b4bf5b41662ec5"),
"name": "Not Applicable",
"sel": false
}
],
"type": "multiple"
}]
}]
And this query:
db.testCollection.aggregate([
{ $unwind: "$parameters" },
{
$match: {
"parameters._id": ObjectId("602b7455f4b4bf5b41662ec1"),
}
},
{
$addFields: {
match: {
$filter: {
input: "$parameters.options",
as: "option",
cond: {
$and: [
{ $eq: ["$$option.id", ObjectId('602b764ff4b4bf5b41662ec2')] },
{ $eq: ["$$option.sel", true] }
]
}
}
}
}
}
])
The result is a new array match with, in this case,
"match": [
{
"id": ObjectId("602b764ff4b4bf5b41662ec2"),
"name": "debug",
"sel": true
}
]
How I can match, for collections, match for example
"id": ObjectId("602b764ff4b4bf5b41662ec2") and
"id": ObjectId("602b764ff4b4bf5b41662ec4")
and have a result array with or two results or empty?
I am not sure it is possible in single condition inside $filter, but you can try with $let,
$let to declare a variable called filtered and store your filtered result
$in to check condition if filtered element size is 2 then return filtered result otherwise blank array
You have to put the number that you are matching number of ids in filter in $eq condition
{
$addFields: {
match: {
$let: {
vars: {
filtered: {
$filter: {
input: "$parameters.options",
as: "option",
cond: {
$and: [
{
$in: [
"$$option.id",
[ObjectId("602b764ff4b4bf5b41662ec2"), ObjectId("602b767df4b4bf5b41662ec3")]
]
},
{ $eq: ["$$option.sel", true] }
]
}
}
}
},
in: {
$cond: [
{ $eq: [{ $size: "$$filtered" }, 2] },
"$$filtered",
[]
]
}
}
}
}
}
Playground