How to update multiple objects in the array in mongoDB? - javascript

How to update multiple objects in the array in MongoDB? Assume that I am retrieving from the client an array of titles that need to be changed.
Example:
Data from client:
[0,3]
Document in the MongoDB:
[
{
_id: 0,
dishes: [
{ title: 0, in_stock: true },
{ title: 1, in_stock: false },
{ title: 2, in_stock: true },
{ title: 3, in_stock: false },
],
},
];
The result should be:
[
{
_id: 0,
dishes: [
{ title: 0, in_stock: false },
{ title: 1, in_stock: false },
{ title: 2, in_stock: true },
{ title: 3, in_stock: true },
],
},
];

You can simply put a aggregation pipeline in your update clause.
db.collection.update({},
[
{
"$addFields": {
"dishes": {
"$map": {
"input": "$dishes",
"as": "d",
"in": {
"$cond": {
"if": {
"$in": [
"$$d.title",
[
0,
3
]
]
},
"then": {
title: "$$d.title",
in_stock: {
"$not": [
"$$d.in_stock"
]
}
},
"else": "$$d"
}
}
}
}
}
}
])
Here is the Mongo playground for your reference.

Related

Mongo Project by referencing external Dictionary

I have a collection in MongoDB:
[
{
"uid": "a1"
},
{
"uid": "a2"
}
]
and a dictionary in my JS code
let dict = { "a1": "ref1", "a1": "ref2" };
I want to do an aggregate that will somehow join the two.
let k = ;
this.model.aggregate([
{
$match: {
uid: { $in: Object.keys(dict) }
}
},
{
$project: {
ref: // here is where I want to add the equivalent reference
}
}
])
The expected output would be something like this:
[{uid: "a1", ref: "ref1"}, {uid: "a2", ref: "ref2}]
Is there a way to get the reference from the dict into the $project?
I don't know if there is an easier way to do it, but here's how I achieved it:
db.collection.aggregate([
{
$match: {
uid: {
$in: [
"a1",
"a2"
]
}
}
},
{
"$project": {
"array": {
"$objectToArray": {
"a1": "ref1",
"a2": "ref2"
}
},
"uid": 1,
}
},
{
"$project": {
"ref": {
"$filter": {
"input": "$array",
"as": "elem",
"cond": {
"$eq": [
"$$elem.k",
"$uid"
]
}
}
},
uid: 1,
},
},
{
"$project": {
ref: {
"$arrayElemAt": [
"$ref.v",
0
]
},
uid: 1,
}
}
])
See it working here. I hope you get the idea and convert it into the nodejs equivalent version.

How to use conditional statement for sort in Mongodb

let me illustrate with an example,
suppose my collection is like this,
products = [
{
id: 1,
name: "a",
offer: true,
expiryDate: "23-03-2022"
},
{
id: 2,
name: "b",
offer: false,//no offer
},
{
id: 3,
name: "c",
offer: true,
expiryDate: "01-01-2021"//already expired
},
{
id: 4,
name: "d",
offer: true,
expiryDate: "01-06-2022"
},
]
I want here, the offered items comes first in descending order,
it should not expire and then the remaining item should come in
descending order so result would be like this
[
{
id: 4,
name: "d",
offer: true,
expiryDate: "01-06-2022"
},
{
id: 1,
name: "a",
offer: true,
expiryDate: "23-03-2022"
},
{
id: 3,
name: "c",
offer: true,
expiryDate: "01-01-2021"
},
{
id: 2,
name: "b",
offer: false,
},
]
db.collection.aggregate([
{
"$match": {}
},
{
"$set": {
"offer": {
"$cond": {
"if": {
"$lt": [
{
"$toDate": "$expiryDate"
},
"$$NOW"
]
},
"then": false,
"else": true
}
},
"expiryDate": {
"$toDate": "$expiryDate"
}
}
},
{
"$sort": {
"expiryDate": -1,
"offer": -1
}
}
])
mongoplayground

Mongo DB query to return count?

I have two collections Course and File.
This is my data from Course collection
[{
_id: 1,
name: "Course1",
price: "100"
},
{
_id: 2,
name: "Course2",
price: "200"
}]
This is my data from files collection
[{
_id: 1,
name: "File1",
isFree: true,
courseId: 1
}
{
_id: 2,
name: "File2",
isFree: false,
courseId: 1
}
{
_id: 3,
name: "File3",
isFree: false,
courseId: 1
}]
I want to retrieve Course 1 with Course name,Count of files which are free,Count of files which are not free.
My attempt:
Course.aggregate([
{$lookup:{
from:"files",
localField: "_id",
foreignField: "courseId",
as: "files"
}},
])
This is my response If I execute my above query:
[
{
"_id": "6161bdcc0aada09d81598840",
"name": "Course1",
"files": [
{
"_id": "6166a0814ad3f56b71232b9c",
"name": "File1.jpeg",
"isFree":true
},
{
"_id": "6166a0814ad3f56b71232b9d",
"name": "File2.jpeg",
"isFree":false
},
{
"_id": "6166a0814ad3f56b71232b9v",
"name": "File3.jpeg",
"isFree":false
}
]
}
]
I want my output as:
[
{
"_id": "6161bdcc0aada09d81598840",
"name": "Course1",
"files": {"free": 1,"paid": 2}
}
]
You can try lookup with pipeline,
$lookup with pipeline, pass courseId in let
$match courseId condition
$group by isFeee and get total count
$project to show required fields in k(key) and v(value) format
$cond to check if isFree true then return "free" otherwise return "paid"
$addFields to update files array
$arrayToObject convert files key-value array to an object
$ifNull to check if property is not exists then set 0
await Course.aggregate([
{
$lookup: {
from: "files",
let: { courseId: "$_id" },
pipeline: [
{ $match: { $expr: { $eq: ["$$courseId", "$courseId"] } } },
{
$group: {
_id: "$isFree",
count: { $sum: 1 }
}
},
{
$project: {
_id: 0,
k: { $cond: ["$_id", "free", "paid"] },
v: "$count"
}
}
],
as: "files"
}
},
{
$addFields: {
files: { $arrayToObject: "$files" }
}
},
{
$addFields: {
"files.free": { $ifNull: ["$files.free", 0] },
"files.paid": { $ifNull: ["$files.paid", 0] }
}
}
])
Playground
Try following:
db.course.aggregate([
{
$lookup: {
from: "files",
localField: "_id",
foreignField: "courseId",
as: "files",
},
},
{
$unwind: {
path: "$files",
preserveNullAndEmptyArrays: true,
},
},
{
$group: {
_id: "$_id",
name: {
$first: "$name",
},
price: {
$first: "$price",
},
free: {
$sum: {
$cond: [
{
$eq: ["$files.isFree", true],
},
1,
0,
],
},
},
paid: {
$sum: {
$cond: [
{
$eq: ["$files.isFree", false],
},
1,
0,
],
},
},
},
},
{
$addFields: {
"files.free": "$free",
"files.paid": "$paid",
},
},
{
$project: {
_id: 1,
name: 1,
files: 1,
price: 1,
},
},
]);

MongoDB aggregate add new field with multiple conditions

I cannot figure to add a new field with multiple conditions in MongoDB. Here is how DB looks like,
const db = [
{
_id: 1,
isActived: false, // Drafted
isScheduled: false,
isExpired: false
},
{
_id: 2,
isActived: true,
isScheduled: true, // Scheduled
isExpired: false
},
{
_id: 3,
isActived: true, // Expired
isScheduled: false,
isExpired: true
},
{
_id: 4,
isActived: true, // Actived
isScheduled: false,
isExpired: false
},
]
Conditions are:
if (!isActived) status = "Draft"
if (isActived && isScheduled) status = "Scheduled"
if (isActived && isExpired) status = "Expired"
if (isActived && !isScheduled && !isExpired) status = "Actived"
I can figure out only one condition and cannot solve it any further. Here is what I did so far
{
$addFields: {
status: {
$cond: [
{
$and: [
{ $eq: ["$isActived", true] },
{ $eq: ["$isScheduled", true] },
],
},
"Actived",
"Scheduled",
],
$cond: [
{
$and: [
{ $eq: ["$isActived", true] },
{ $eq: ["$isExpired", true] },
],
},
"Actived",
"Expired",
],
},
},
}
The result is not what I expected.
Any suggestion. Thank You.
You can concatenate if/else in this way:
Pseudocode:
if !isActived:
return "Draft"
else
if !isScheduled && !isExpired:
return "Actived"
else
if isScheduled:
return "Scheduled"
else
return "Expired" //<-- Since one of "isScheduled" and "isExpired" should be true
Take care on last line where may you can have isScheduled and isExpired to true, so you logic can change.
db.collection.aggregate([
{
"$set": {
"status": {
"$cond": {
"if": {
"$eq": [
"$isActived",
false
]
},
"then": "Draft",
"else": {
"$cond": {
"if": {
"$and": [
{
"$eq": [
"$isExpired",
false
]
},
{
"$eq": [
"$isScheduled",
false
]
}
]
},
"then": "Actived",
"else": {
"$cond": {
"if": {
"$eq": [
"$isScheduled",
true
]
},
"then": "Scheduled",
"else": "Expired"
}
}
}
}
}
}
}
}
])
Example here
Simple nested conditions, working solution
db.collection.aggregate([
{
$addFields: {
status: {
$cond: [
{
$and: [
{ $eq: [ "$isActived", true ] },
{ $eq: [ "$isScheduled", false ] },
{ $eq: [ "$isExpired", false ] },
],
},
"Actived",
{
$cond: [
{
$and: [
{ $eq: [ "$isActived", true ] },
{ $eq: [ "$isExpired", true ] },
],
},
"Expired",
{
$cond: [
{
$and: [
{ $eq: [ "$isActived", true ] },
{ $eq: [ "$isScheduled", true ] },
],
},
"Scheduled",
{
$cond: [
{
$and: [
{ $eq: [ "$isActived", false ] },
],
},
"Draft",
null,
],
},
],
},
],
},
],
},
},
},
])

Aggregate data from nested array

I need help with the aggregate framework.
I have a model (currencies field can contain more than one object):
const schema = new mongoose.Schema({
country: { type: String },
code: { type: String },
region: [{
name: { type: String },
path: { type: Array },
city: [{
name: { type: String },
path: { type: Array },
latitude: { type: String },
longitude: { type: String },
}],
}],
currencies: [{
code: { type: String },
name: { type: String },
symbol: { type: String },
}],
})
And I need to receive all currencies without duplicates.
Received data can view like this:
[
{ code: 'string', name: 'sting', symbol: 'string' },
{ code: 'string', name: 'sting', symbol: 'string' },
...
]
// or like this:
[
currencies: [
{ code: 'string', name: 'sting', symbol: 'string' },
{ code: 'string', name: 'sting', symbol: 'string' },
...
]
]
I try to create a query
Geo.aggregate([
{
$group: {
_id: null,
currencies: { $addToSet: '$currencies' },
},
},
])
but receive this data with duplicates and it has many nested arrays:
[
{
"_id": null,
"currencies": [
[
{
"_id": "5cd9486248989616a411fac5",
"code": "JPY",
"name": "Japanese yen",
"symbol": "¥"
}
],
[
{
"_id": "5cd9491a48989616a411fb47",
"code": "TRY",
"name": "Turkish lira",
"symbol": null
}
],
I try this query:
Geo.aggregate([
{
$addFields: {
code: '$currencies.code',
name: '$currencies.name',
symbol: '$currencies.symbol',
},
},
])
But I receive error "TypeError: item is not iterable".
I need little help )
Db data views like this:
{
"_id": {
"$oid": "5c3334a8871695568817eadf"
},
"country": "Singapore",
"code": "sg",
"region": [
{
"path": [
"Singapore"
],
"_id": {
"$oid": "5c3366c63d92ac6e531e05c0"
},
"city": [],
"name": "Central Singapore Community Development Council"
},
....
],
"__v": 0,
"currencies": [
{
"_id": {
"$oid": "5cd948ec48989616a411fb28"
},
"code": "BND",
"name": "Brunei dollar",
"symbol": "$"
},
{
"_id": {
"$oid": "5cd948ec48989616a411fb27"
},
"code": "SGD",
"name": "Singapore dollar",
"symbol": "$"
}
]
}
In aggregate pipeline first you need to unwind the currencies array and then group them by condition to get desired result.
Geo.aggregate([
{
$unwind: '$currencies'
},
{
$group: {
_id: null,
currencies: { $addToSet: '$currencies' },
},
},
])
For more information you can look into documentation here
db.temp.aggregate([
{$project : {currencies : 1}},
{$unwind: "$currencies"},
{
$addFields: {
currencyHash: {
$concat : ['$currencies.code', "--", "$currencies.name", "--", "$currencies.symbol"]
}
}
},
{
$group: {
_id: "$currencyHash",
currency : {
$first : "$currencies"
}
}
},
{
$project: {
code : "$currency.code",
name : "$currency.name",
symbol : "$currency.symbol"
}
},
{
$project: {
_id : 0,
currency : 0
}
}
]).pretty()

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