I have this one schema
{
_id: "123456",
id: "123",
inventory: [
{
id: "foo",
count: 0
},
{
id: "bar",
count: 3
}
]
}
I wanted every "count" keys in the inventory array to be "price" which will look like this at the end:
{
_id: "123456",
id: "123",
inventory: [
{
id: "foo",
price: 0
},
{
id: "bar",
price: 3
}
]
}
And I've tried this
Model.updateOne({ id: "123" }, { $unset: { inventory: [{ count: 1 }] } } )
But it seems to be deleting the "inventory" field itself
The first thing here is to try to use $rename but how the docs explain:
$rename does not work if these fields are in array elements.
So is necessary to look for another method. So you can use this update with aggregation query:
This query uses mainly $map, $arrayToObject and $objectToArray. The trick here is:
Create a new field called inventory (overwrite existing one)
Iterate over every value of the array with $map, and then for each object in the array use $objectToArray to create an array and also iterate over that second array using again $map.
Into this second iteration create fields k and v. Field v will be the same (you don't want to change the value, only the key). And for field k you have to change only the one whose match with your condition, i.e. only change from count to price. If this condition is not matched then the key remain.
db.collection.update({},
[
{
$set: {
inventory: {
$map: {
input: "$inventory",
in: {
$arrayToObject: {
$map: {
input: {$objectToArray: "$$this"},
in: {
k: {
$cond: [
{
$eq: ["$$this.k","count"]
},
"price",
"$$this.k"
]
},
v: "$$this.v"
}
}
}
}
}
}
}
}
])
Example here
Related
For example, I have something in my database like in customers collection.
{
Max: {
shoping_list: {
food: { Pizza: 2, Ramen: 1, Sushi: 5 }
}
},
John: {
shoping_list: {
food: { Pizza: 2, Ramen: 1, Burger: 1 }
}
}
}
In my backend, I want to get the sum of food
const request = await customers.aggregate([
{
$group: {
_id: null,
Pizza: {
$sum: '$shoping_list.food.Pizza',
},
Is there a way how to update or get the sum automatically without manually writing every food from the shopping_list?
The design of the document may lead the query looks complex but still achievable.
$replaceRoot - Replace the input document with a new document.
1.1. $reduce - Iterate the array and transform it into a new form (array).
1.2. input - Transform key-value pair of current document $$ROOT to an array of objects such as: [{ k: "", v: "" }]
1.3. initialValue - Initialize the value with an empty array. And this will result in the output in the array.
1.4. in
1.4.1. $concatArrays - Combine aggregate array result ($$value) with 1.4.2.
1.4.2. With the $cond operator to filter out the document with { k: "_id" }, and we transform the current iterate object's v shoping_list.food to the array via $objectToArray.
$unwind - Deconstruct the foods array into multiple documents.
$group - Group by foods.k and perform sum for foods.v.
db.collection.aggregate([
{
$replaceRoot: {
newRoot: {
foods: {
$reduce: {
input: {
$objectToArray: "$$ROOT"
},
initialValue: [],
in: {
$concatArrays: [
"$$value",
{
$cond: {
if: {
$ne: [
"$$this.k",
"_id"
]
},
then: {
$objectToArray: "$$this.v.shoping_list.food"
},
else: []
}
}
]
}
}
}
}
}
},
{
$unwind: "$foods"
},
{
$group: {
_id: "$foods.k",
sum: {
$sum: "$foods.v"
}
}
}
])
Demo # Mongo Playground
I have documents that consist of an array of objects, and each object in this array consists of another array of objects.
For simplicity, irrelevant fields of the documents were omitted.
It looks like this (2 documents):
{
title: 'abc',
parts: [
{
part: "verse",
progressions: [
{
progression: "62a4a87da7fdbdabf787e47f",
key: "Ab",
_id: "62b5aaa0c9e9fe8a7d7240d3"
},
{
progression: "62adf477ed11cbbe156d5769",
key: "C",
_id: "62b5aaa0c9e9fe8a7d7240d3"
},
],
_id: "62b5aaa0c9e9fe8a7d7240d2"
},
{
part: "chorus",
progressions: [
{
progression: "62a4a51b4693c43dce9be09c",
key: "E",
_id: "62b5aaa0c9e9fe8a7d7240d9"
}
],
_id: "62b5aaa0c9e9fe8a7d7240d8"
}
],
}
{
title: 'def',
parts: [
{
part: "verse",
progressions: [
{
progression: "33a4a87da7fopvvbf787erwe",
key: "E",
_id: "62b5aaa0c9e9fe8a7d7240d3"
},
{
progression: "98opf477ewfscbbe156d5442",
key: "Bb",
_id: "62b5aaa0c9e9fe8a7d7240d3"
},
],
_id: "12r3aaa0c4r5me8a7d72oi8u"
},
{
part: "bridge",
progressions: [
{
progression: "62a4a51b4693c43dce9be09c",
key: "C#",
_id: "62b5aaa0c9e9fe8a7d7240d9"
}
],
_id: "62b5aaa0rwfvse8a7d7240d8"
}
],
}
The parameters that the client sends with a request are an array of objects:
[
{ part: 'verse', progressions: ['62a4a87da7fdbdabf787e47f', '62a4a51b4693c43dce9be09c'] },
{ part: 'chorus', progressions: ['62adf477ed11cbbe156d5769'] }
]
I want to retrieve, through mongodb aggregation, the documents that at least one of objects in the input array above is matching them:
In this example, documents that have in their parts array field, an object that has the value 'verse' in the part property and one of the progressions id's ['62a4a87da7fdbdabf787e47f', '62a4a51b4693c43dce9be09c'] in the progression property in one of the objects in the progressions property, or documents that have in their parts array field, an object that has the value 'chorus' in the part property and one of the progressions id's ['62adf477ed11cbbe156d5769'] in the progression property in one of the objects in the progressions property.
In this example, the matching document is the first one (with the title 'abc'), but in actual use, there might be many matching documents.
I tried to create an aggregation pipeline myself (using the mongoose 'aggregate' method):
// parsedProgressions = [
// { part: 'verse', progressions: ['62a4a87da7fdbdabf787e47f', '62a4a51b4693c43dce9be09c'] },
// { part: 'chorus', progressions: ['62adf477ed11cbbe156d5769'] }
// ]
songs.aggregate([
{
$addFields: {
"tempMapResults": {
$map: {
input: parsedProgressions,
as: "parsedProgression",
in: {
$cond: {
if: { parts: { $elemMatch: { part: "$$parsedProgression.part", "progressions.progression": mongoose.Types.ObjectId("$$parsedProgression.progression") } } },
then: true, else: false
}
}
}
}
}
},
{
$addFields: {
"isMatched": { $anyElementTrue: ["$tempMapResults"] }
}
},
{ $match: { isMatched: true } },
{ $project: { title: 1, "parts.part": 1, "parts.progressions.progression": 1 } }
]);
But it didn't work - as I understand it, because the $elemMatch can be used only in the $match stage.
Anyway, I guess I overcomplicated the aggregation pipeline, so I will be glad if you can fix my aggregation pipeline/offer a better working one.
This is not a simple case as these are both nested arrays and we need to match both the part and the progressions, which are not on the same level
One option looks complicated a bit, but keeps your data small:
In order to make things easier, $set a new array field called matchCond which includes an array called progs containing the parts.progressions. To each sub-object inside it insert the matching progressions input array. We do need to be careful here and handle the case where there is no matching progressions input arrayprogressions input array, as this is the case for the "bridge" part on the second document.
Now we just need to check if for any of these progs items, the progression field is matching one option in input array. This is done using $filter, and $rediceing the number of results.
Just match document which have results and format the answer
db.collection.aggregate([
{
$set: {
matchCond: {
$map: {
input: "$parts",
as: "parts",
in: {progs: {
$map: {
input: "$$parts.progressions",
in: {$mergeObjects: [
"$$this",
{input: {progressions: []}},
{input: {$first: {
$filter: {
input: inputData,
as: "inputPart",
cond: {$eq: ["$$inputPart.part", "$$parts.part"]}
}
}}}
]}
}
}}
}
}
}
},
{$set: {
matchCond: {
$reduce: {
input: "$matchCond",
initialValue: 0,
in: {$add: [
"$$value",
{$size: {
$filter: {
input: "$$this.progs",
as: "part",
cond: {$in: ["$$part.progression", "$$part.input.progressions"]}
}
}
}
]
}
}
}
}
},
{$match: {matchCond: {$gt: 0}}},
{$project: {title: 1, parts: 1}}
])
See how it works on the playground example
Another option is to use $unwind, which looks simple, but will duplicate your data, thus, likely to be slower:
db.collection.aggregate([
{$addFields: {inputData: inputData, cond: "$parts"}},
{$unwind: "$cond"},
{$unwind: "$cond.progressions"},
{$unwind: "$inputData"},
{$match: {
$expr: {
$and: [
{$eq: ["$cond.part", "$inputData.part"]},
{$in: ["$cond.progressions.progression", "$inputData.progressions"]}
]
}
}
},
{$project: {title: 1, parts: 1}}
])
See how it works on the playground example - unwind
There are several options between these two...
So I tried several ways, but I can't, I can modify several objects with the same key but I can't modify any with different keys, if anyone can help me is quite a complex problem
{
id: 123,
"infos": [
{ name: 'Joe', value: 'Disabled', id: 0 },
{ name: 'Adam', value: 'Enabled', id: 0 }
]
};
In my database I have a collection with an array and several objects inside which gives this.
I want to modify these objects, filter by their name and modify the value.
To give you a better example, my site returns me an object with the new data, and I want to modify the database object with the new object, without clearing the array, the name key never changes.
const object = [
{ name: 'Joe', value: 'Hey', id: 1 },
{ name: 'Adam', value: 'None', id: 1 }
];
for(const obj in object) {
Schema.findOneAndUpdate({ id: 123 }, {
$set: {
[`infos.${obj}.value`]: "Test"
}
})
}
This code works but it is not optimized, it makes several requests, I would like to do everything in one request, and also it doesn't update the id, only the value.
If anyone can help me that would be great, I've looked everywhere and can't find anything
My schema structure
new Schema({
id: { "type": String, "required": true, "unique": true },
infos: []
})
I use the $addToSet method to insert objects into the infos array
Try This :
db.collection.update({
id: 123,
},
{
$set: {
"infos.$[x].value": "Value",
"infos.$[x].name": "User"
}
},
{
arrayFilters: [
{
"x.id": {
$in: [
1
]
}
},
],
multi: true
})
The all positional $[] operator acts as a placeholder for all elements in the array field.
In $in you can use dynamic array of id.
Ex :
const ids = [1,2,..n]
db.collection.update(
//Same code as it is...
{
arrayFilters: [
{
"x.id": {
$in: ids
}
},
],
multi: true
})
MongoPlayGround Link : https://mongoplayground.net/p/Tuz831lkPqk
Maybe you look for something like this:
db.collection.update({},
{
$set: {
"infos.$[x].value": "test1",
"infos.$[x].id": 10,
"infos.$[y].value": "test2",
"infos.$[y].id": 20
}
},
{
arrayFilters: [
{
"x.name": "Adam"
},
{
"y.name": "Joe"
}
],
multi: true
})
Explained:
You define arrayFilters for all names in objects you have and update the values & id in all documents ...
playground
My question is pretty similar to: MongoDB Aggregation join array of strings to single string, but instead of pure Array, like: ['Batman', 'Robin'] I have Array of objects:
_id: 1,
field_value: [
{
_id: 2,
name: "Batman"
},
{
_id: 3,
name: "Robin"
}
]
I am trying to use $reduce but got error instead.
I want to receive the following result:
_id: 1,
field_value: "Batman, Robin" /** <= String value */
or at least array of property values:
_id: 1,
field_value: ["Batman", "Robin"] /** <= Array of strings (name property) */
My MongoPlayground data example
You need the same approach with $reduce, $$this represents a single field_value entity so you need $$this.name:
db.collection.aggregate([
{
$project: {
field_value: {
$reduce: {
input: "$field_value",
initialValue: "",
in: {
$concat: [
"$$value",
{ $cond: [ { $eq: [ "$$value", "" ] }, "", "," ] },
{ $toString: "$$this.name" }
]
}
}
}
}
}
])
Mongo Playground
Example
This is an example document:
{
row: [
{
identifier: "a"
value: 52
},
{
identifier: "b"
value: 22
},
{
identifier: "c"
value: 36
}
]
}
Problem
Let's say I need the arrays first (identifier c) and last element (identifier c) but only where value is greater than 5 within the last element (identifier c).
Basically, I would like to combine these two conditions:
Be identifier a or identifier c
be greater than 5 when you are identifier c.
Both conditions should be part of an aggregation pipeline. The result should look like this:
[
{
_id: 1,
row: [{ identifier: "a", value: 52}, { identifier: "c", value: 22}]
} //, ...
]
Approach
I tried many ways but nothing worked. Last thing I tried was $cond, but that also didn't work:
'if': {
'row.identifier': c,
'then': {
'row.value': {$gt: 5}
}
}
Here's how can filter the row array to only contain what you want:
db.collection.aggregate({
$project: {
row: { // create a new field called "row" which will hold...
$filter: { // ...the filtered contents...
input: "$row", // ...of the existing "row" array...
as: "this", // ...use the variable "$$this" to refer to the current element...
cond: { // ...and only keep items where...
$or: [ // ...either...
{ $eq: [ "$$this.identifier", "a" ] }, // ...the "identifier" field is equal to "a"...
{ $and: [ // ...or both...
{ $eq: [ "$$this.identifier", "c" ] }, // ...the "identifier" field is equal to "c"...
{ $gt: [ "$$this.value", 5 ] } // ...and the "value" field is greater than 5
]}
]
}
}
}
}
})