I wonder how I could insert array of objects to Mongo collection "root-level documents" with own pre-defined _id values.
I have tried db.MyCollection.insert(array); but it creates nested documents under one single generated _id in MongoDB.
var array = [
{ _id: 'rg8nsoqsxhpNYho2N',
goals: 0,
assists: 1,
total: 1 },
{ _id: 'yKMx6sHQboL5m8Lqx',
goals: 0,
assists: 1,
total: 1 }];
db.MyCollection.insert(array);
What I want
db.collection.insertMany() is what you need (supported from 3.2):
db.users.insertMany(
[
{ name: "bob", age: 42, status: "A", },
{ name: "ahn", age: 22, status: "A", },
{ name: "xi", age: 34, status: "D", }
]
)
output:
{
"acknowledged" : true,
"insertedIds" : [
ObjectId("57d6c1d02e9af409e0553dff"),
ObjectId("57d6c1d02323d119e0b3c0e8"),
ObjectId("57d6c1d22323d119e0b3c16c")
]
}
Why not iterate over the array objects, and insert them one at a time?
array.forEach((item) => db.MyCollection.insert(item));
Go through this Link To get Exact Outcome the way you want:
https://docs.mongodb.org/manual/tutorial/insert-documents/#insert-a-document
You can use MongoDB Bulk to insert multiple document in one single call to the database.
First iterate over your array and call the bulk method for each item:
bulk.insert(item)
After the loop, call execute:
bulk.execute()
Take a look at the refereed documentation to learn more.
Related
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
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
Can someone please help me understand how to make this work. Everytime I feel like I start to understand arrays and objects in Javascript it turns out that I still don't.
I'm trying to get the average of all prices in the following datastructure by using lodash meanBy
[
{
date: "2019-12-17",
items: [
{ id: "1", state: "accepted", price: "90.5" },
{ id: "2", state: "rejected", price: "20.0" },
{ id: "3", state: "open", price: "10.5" },
]
},
{
date: "2019-12-18",
items: [
{ id: "4", state: "open", price: "450.0" },
{ id: "5", state: "rejected", price: "40.1" },
{ id: "6", state: "accepted", price: "50.9" },
]
}
]
If you provide the answer, can you also please try to explain how you select something nested in items, because that's as far as I get before I get lost.
In this case instead of selecting nested values, it's easier to flatten the items to a single array, and then apply _.meanBy(). In addition, the prices are strings, and not numbers, so you'll need to convert them.
Flatten the items to a single array with Array.flatMap(), and then use _.meanBy(), and get the numeric values of the prices:
const data = [{"date":"2019-12-17","items":[{"id":"1","state":"accepted","price":"90.5"},{"id":"2","state":"rejected","price":"20.0"},{"id":"3","state":"open","price":"10.5"}]},{"date":"2019-12-18","items":[{"id":"4","state":"open","price":"450.0"},{"id":"5","state":"rejected","price":"40.1"},{"id":"6","state":"accepted","price":"50.9"}]}]
const result = _.meanBy(_.flatMap(data, 'items'), o => +o.price)
console.log(result)
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>
Another approach is to get the general average, by getting the average of each items array separately , and then getting the average of all averages.
const data = [{"date":"2019-12-17","items":[{"id":"1","state":"accepted","price":"90.5"},{"id":"2","state":"rejected","price":"20.0"},{"id":"3","state":"open","price":"10.5"}]},{"date":"2019-12-18","items":[{"id":"4","state":"open","price":"450.0"},{"id":"5","state":"rejected","price":"40.1"},{"id":"6","state":"accepted","price":"50.9"}]}]
const result = _.meanBy(data, ({ items }) => _.meanBy(items, o => +o.price))
console.log(result)
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>
So i've got a single page application running via MEAN Stack. I've got the following scheme/model for a Klausur (Klausur is german for exam, i want to manage exams).
var KlausurSchema = new Schema(
{
name: String,
semester: String,
krankmeldungen: [Number],
aufgaben: [{
name: String,
punkte: Number
}],
studenten: [{
matrnr: Number,
vorname: String,
nachname: String,
bewertung: [{
punkte: Number
}],
pversuch: String,
pvermerk: String,
freiverm: String,
labnr: Number,
porgnr: Number,
aenddat: String
}]
}
);
Multiple users can edit the entrys, otherwise i would just overwrite the entry. I want to have a table consisting of the "studenten" (students), is it possible to PUSH one student to my "studenten" without PUTTING (edit) the whole "Klausur", i.e. I want to push information to an array without overwriting the whole db entry!
Thanks in advance!
Please Check Docs
If you want to insert new students array. you can use below mentioned MongoDB query.
Using MongoDB
db.klausur.update(
{ name: "David" },
$addToSet: {
studenten: {
$each: [
{
matrnr: 123,
vorname: "ABC",
nachname: "XYZ",
bewertung: [{
punkte: 123
}]
},
{
matrnr: 124,
vorname: "ABCD",
nachname: "XYZA",
bewertung: [{
punkte: 1234
}]
}]
}
);
Using Mongoose
ModelName.update(
{ name: "David" },
$addToSet: {
studenten: {
$each: [
{
matrnr: 123,
vorname: "ABC",
nachname: "XYZ",
bewertung: [{
punkte: 123
}]
}]
}
);
you can also use $push instead of $addToSet. but $addToSet handle duplicates insertion issue. One more thing if you want to add single student object then just use above query without $each. for example
db.klausur.update(
{ name: "David" },
$addToSet: {
studenten: {
matrnr: 123,
vorname: "ABC",
nachname: "XYZ",
bewertung: [{
punkte: 123
}]
}
}
);
Pass an object to be updated to native mongoDB update query.
The pseudo query will be,
db.model.update(selector, objectToUpsert);
db.student.update(
{ name: "David" },
{
name: "Will",
marks: 75,
grade: A
},
{ upsert: true }
)
First find Klausur=exam say
Klausur.findOne({_id:sample_id}).exec(function (error, closure){
closure.students.push(newstudentobject);
closure.save();
})
I have the following documents:
{
_id: 1
title: "oneItem"
},
{
_id: 2,
title: "twoItem"
}
When I try to find these documents by using the following command:
db.collection.documents.find({_id: {$in: [1, 2]}});
I get these two documents but when I try to find these documents by using the following query:
db.collection.documents.find({_id: {$all: [1, 2]}});
I get nothing. Can you explain what's the problem? Basically I need to find all documents with _id 1 and 2 and if none exist then fail.
The reasoning is actually quite simple in that $in and $all have two completely different functions. The documentation links are there, but to explain:
Consider these documents:
{
_id: 1,
items: [ "a", "b" ]
},
{
_id: 2,
items: [ "a", "b", "c" ]
}
$in - provides a list of arguments that can possibly match the value in the field being tested. This would match as follows:
db.collection.find({ items: {$in: [ "a", "b", "c" ] }})
{
_id: 1,
items: [ "a", "b" ]
},
{
_id: 2,
items: [ "a", "b", "c" ]
}
$all - provides a list where the field being matched is expected to be an array and all of the listed elements are present in that array. E.g
db.collection.find({ items: {$all: [ "a", "b", "c" ] }})
{
_id: 2,
items: [ "a", "b", "c" ]
}
Hence why your query does not return a result, the field is not an array and does not contain both elements.
The MongoDB operator reference is something you should really read through.
As your your statement, ["I need to find all documents with _id 1 and 2 and if someone from them does not exists then fail."], matching various criteria is easy as you see in the usage of $in. Your problem is you want a whole set to match or otherwise return nothing ("fail"). This I have already explained to you an some length in a previous question, but to re-iterate:
db.collection.aggregate([
// Match on what you want to find
{$match: { list: {$in: [1,2]} }},
// Add the found results to a distinct *set*
{$group: { _id: null, list: {$addToSet: "$_id"} }},
// Only return when *all* the expected items are in the *set*
{$match: { list: {$all: [1,2]} }}
])
So after that manipulation, this will only return a result if all of the items where found. That is how we use $all to match in this way.