I need some help with MongoDb. I need to check if an object exists in the database. If it's true, then I need to check if this object has a specific element into array (Products). If not, I need to create this object(Order) with this element(Cookie) in to array(Products).
Example data:
Order {
_id: ObjectId("580bc55f54101f1d18152d88"),
code: "AVG223424",
products: [
{
name: "Cookie"
},
{
name: "Soda"
}
]
}
Finally, what is the better implementation?
Assuming you are using a collection with the name 'Orders'
db
.Orders
.update({
code: "12345"
}, {
$addToSet: {
products: {
name: "Cookie"
}
},
$setOnInsert: {
code: "12345"
}
}, {
upsert: true
});
This query looks for a document with the same 'code,' and if found, will add the object '{name: "Cookie"}' if there is no other Object with the same key/val pairs. If the document does not exist, the '$setOnInsert' command will set the specified fields only if a new document is created.
Related
I have query in MongoDB for which I'm trying to upsert an inner nested attribute that contains a dot(.) in the key. E.g. a document might look something like: (below is a fictitious example just to highlight the constraint I'm facing.)
const person = {
name: 'Peter',
address: {
'NY.postalCode': 12345,
'CA.postalCode': 23456,
}
}
However, when I try to update one of the nested attribute in address with the below $set operation, I get an additional object NY under address and its subKey postalCode as a result, instead of the flattened attribute within address.
await Person.findByIdAndUpdate(id, {
$set: {
'address.NY.postalCode': 98765,
}
}, { new: true });
// Output
{
name: 'Peter',
address: {
'NY.postalCode': 12345,
'CA.postalCode': 23456,
NY: {
postalCode: 98765,
}
}
}
I've tried using the escape character for dot (\u002e), but get the same output. Also, I have seen some new features for setting fields but only in Mongo v5: https://www.mongodb.com/docs/manual/reference/operator/aggregation/setField/#mongodb-expression-exp.-setField. However, we're using Mongo v4.2 and would not be able to upgrade until a while later.
Would like to check if there are any means to $set nested attributes in address that don't completely replace the address object? i.e. to be able to specifically upsert an inner attribute within address object?
For example, is it possible to use the aggregation framework to workaround this?
I've tried something like the below, but it didn't work - not sure if its something that I did wrong or its probably not possible to use the aggregation pipeline..
Person.aggregate([
{
$match: {
_id: id,
},
},
{
$replaceRoot: { newRoot: {
$mergeObjects: [
'$$ROOT.address',
{
'NY.postalCode': 98765,
},
],
} },
},
]);
For your scenario, you need to achieve the update with aggregation pipeline.
Use $literal to escape the field name with dot.
Via $mergeObjects to merge current address object with { NY.postalCode': 98765 }.
db.collection.update({
"_id": ObjectId("5a934e000102030405000000")
},
[
{
$set: {
"address": {
$mergeObjects: [
"$address",
{
$literal: {
"NY.postalCode": 98765
}
}
]
}
}
}
],
{
new: true
})
Demo # Mongo Playground
I'm trying to update and object inside array in MongoDB.
my model is:
let userSchema = new mongoose.Schema({
userName: {
type: String
},
password: {
type: String
},
history: []
});
And inside history each element is from the next type:
id, array(named ing_array) and boolean field called favorite.
I'm trying to update the favorite field with mongoose with the userName and the id.
I tried to do this query and I didn't succed.
Could some one tell me whats worng?
[object photo]: https://i.stack.imgur.com/2mYpP.png
User.findOneAndUpdate(
{ "userName": user_name, "history.id": id },
{ "$set": { "history.$.favorite": true }}
);
You have to use arrayFilters in this way:
db.collection.update({
"userName": "uname",
"history.id": 1
},
{
"$set": {
"history.$[element].favorite": false
}
},
{
"arrayFilters": [
{
"element.id": 1
}
]
})
Note that update query has the format: update(query, update, options) (Check the docs).
When you do { "userName": user_name, "history.id": id } you are telling mongo "Give me all documents where userName is user_name and array history has an id with value id. This return all history array because it belows to the document.
To update an specific object into the array is neccessary to use arrayFilters to tell mongo which object do you want to update. In this case the object where id is equal to 1. You can use as you want to match wit your requirements.
Example here
I would like to update each elements (object) in an array of a company.
Here my actual data :
{
_id: ObjectId("60d31024860ce0400b586111")
contracts:
[
{
name: 1.pdf
url: "https://someurl"
createdAt: 2021-06-23T10:42:44.594+00:00
}
{
name: 2.pdf
url: "https://someurl"
}
{
name: 3.pdf
url: "https://someurl"
}
]
}
I would like to add a defined date on each object (in contracts) that has no "updatedAt" key.
Here what I tried :
db.companies.update({ _id: ObjectId("60d31024860ce0400b586111"),"contracts.createdAt": { $exists: false } },{ $set: { "contracts.$.createdAt": "test" } })
but I got this error :
"The positional operator did not find the match needed from the query."
I have also tried this and it works, but I don't wanna query by file name. I just wanna add "createdAt" on each elements found that has no "createdAt"
db.companies.update({ "contracts.name": "2.pdf" },{ $set: { "contracts.$.createdAt": "atest" } })
I think you need to use the filtered position operator:
$ - updates the first matched array element
$[] - updates all the matched elements with a specific condition
The specific condition is mentioned in the arrayFilters key.
db.students.update(
{ },
{ $set: { "contracts.$[element].createdAt" : "atest"} },
{ multi: true,
arrayFilters: [ { "element.createdAt": { $exists: false } } ]
}
)
multi - true is to apply the operation on all the matching documents.
Also notice, how the first query parameter is empty, which means the query runs for all documents. I used it based on the second query you wrote but you can also add in an ObjectID query there.
I need to define the mongoose schema for for nested documents which is given below.
Documents:
"Options":[{"Value":["28","30","32","34","36","38","40","42","44","46"],"_id":{"$oid":"5de8427af55716115dd43c8f"},"Name":"Size"},{"Value":["White"],"_id":{"$oid":"5de8427af55716115dd43c8e"},"Name":"Colour"}]
I was declaring like below but its not working.
const Product = new Schema(
{
Options: [{ value: { _id: ObjectId, Name: String } }]
},
{
timestamps: {
createdAt: "createdAt",
updatedAt: "updatedAt"
},
collection: "products"
}
);
Here I need the schema where if i will directly add/update the same document then it will be added.
You need to modify your schema like this :
{
Options: [ new Schema ({ value: [...], _id: Schema.Types.ObjectId, Name: String })]
}
This is the way to create an array of subdocuments with Mongoose. If you don't use the "new Schema" key words, you are actually creating a field with type "Mixed", which needs a different way to handle updates.
You can also omit the _id, it should be added automatically.
You can find more information on subdocument on this page :
https://mongoosejs.com/docs/subdocs.html
...and on mixed type fields : https://mongoosejs.com/docs/schematypes.html#mixed
...which will explain shortly the problem.
{
Options: [ new Schema ({ _id: mongoose.Types.ObjectId(),value: [String], Name: String } })]
}
I'm trying to get all documents in a collection based on a subdocument array values. This is my data structure in the collection i'm seeking:
{
_id: ObjectId('...'),
name: "my event",
members:
[
{
_id: ObjectId('...'),
name: "family",
users: [ObjectId('...'),ObjectId('...'),ObjectId('...')]
},
{
_id: ObjectId('...'),
name: "work",
users: [ObjectId('...'),ObjectId('...'),ObjectId('...')]
}
]
}
I should point out that the schema of these objects are defined like so:
Events:
{
name: { type: String },
members: {type: [{ type: ObjectId, ref: 'MemberGroup' }], default:[] }
}
MemberGroup:
{
name: { type: String },
users: [{type: mongoose.Schema.Types.ObjectId, ref: 'User'}]
}
and of course User is just an arbitrary object with an id.
What i'm trying to fetch: i want to retrieve all events which has a specific user id in its member.users field.
i'm not sure if its event possible in a single call but here is what i've tried:
var userId = new mongoose.Schema.ObjectId('57d9503ef10d5ffc08d6b8cc');
events.find({members: { $elemMatch : { users: { $in: [userId]} } }})
this syntax work but return no elements even though i know there are matching elements (using robomongo to visualize the db)
So after a long search in stackoverflow i came across the good answare here:
MongoDB: How to find out if an array field contains an element?
my query changed to the following which gave me my desired result:
var userId = new mongoose.Schema.ObjectId('57d9503ef10d5ffc08d6b8cc');
events.find({}, {members: { $elemMatch : { users: { $eq: userId} } }})
notice the use of the second find parameter to specify the query limit instead of the first one (which is odd)