I have a document like this
{
users: [
{
name: 'John',
id: 1
},
{
name: 'Mark',
id: 2
},
{
name: 'Mike',
id: 3
},
{
name: 'Anna',
id: 4
}
]
}
and I want to remove users from the array with ids 2 and 4. To do that I execute the following code:
const documents = [
{
id: 2
},
{
id: 4
},
]
Model.updateOne({ document_id: 1 }, { $pull: { users: { $in: documents } } });
But it doesn't remove any user.
Could you say me what I'm doing wrong and how to achieve the needed result?
This works if you can redefine the structure of your documents array:
const documents = [2, 4]
Model.updateOne({ document_id: 1 }, { $pull: { users: { id: { $in: documents } } } })
Related
I've worked on this for about an hour now and I can't figure anything out that works so sorry if this is obvious.
I want my query to only return results where every result matches, but right now it returns a result if at least one match is found.
My document looks like this...
{
country: 'Great Britain',
data: [
{
school: 'King Alberts',
staff: [
{
name: 'John',
age: 37,
position: 'Head Teacher'
},
{
name: 'Grace',
age: 63,
position: 'Retired'
},
{
name: 'Bob',
age: 25,
position: 'Receptionist'
}
]
},
{
school: 'St Johns',
staff: [
{
name: 'Alex',
age: 22,
position: 'Head of Drama'
},
{
name: 'Grace',
age: 51,
position: 'English Teacher'
},
{
name: 'Jack',
age: 33,
position: 'Receptionist'
}
]
},
// ... more schools
]
}
The query I'm currently making looks like...
{ 'data.staff.name': { $in: names } }
and the 'names' array that is being provided looks like ['Bob', 'Grace', 'John', 'Will', 'Tom']. Currently both schools are being returned when I make this query, I think it's because the 'names' array contains 'Grace' which is a name present at both schools and so the document it matching. Does anyone know if there's a query I could make so mongodb only returns the school object if every name in the 'names' array is a member of staff at the school?
You need to use the aggregation pipeline for this, after matching the document we'll just filter out the none matching arrays, like so:
db.collection.aggregate([
{
$match: {
"data.staff.name": {
$in: names
}
}
},
{
$addFields: {
data: {
$filter: {
input: "$data",
cond: {
$eq: [
{
$size: {
"$setIntersection": [
"$$this.staff.name",
names
]
}
},
{
$size: "$$this.staff"
}
]
}
}
}
}
}
])
Mongo Playground
I have the following array of objects...
[
{
_id: 'dfjkldsjfkldjas',
name: 'will'
},
{
_id: 'fdsfdakjdhfaskh',
name: 'bob'
},
{
_id: 'fdsfdasfdfewrfq',
name: 'tom'
}
]
Is there a way to search a mongodb collection for documents that match these _id's and then $set the name in the document all in one query? Maybe using updateMany?
You can use a bulkWrite to achieve this. First map your array and transform the data like so:
const data = [
{
_id: 'dfjkldsjfkldjas',
name: 'will'
},
{
_id: 'fdsfdakjdhfaskh',
name: 'bob'
},
{
_id: 'fdsfdasfdfewrfq',
name: 'tom'
}
]
const bulkData = data.map(item => (
{
updateOne: {
filter: { _id: item._id },
update: { $set: { name: item.name }}
}
})
);
Then you use the method bulkWrite to save the multiple data.
db.yourCollection.bulkWrite(bulkData);
You also don't have to use the same DB operation for every entry, you can use different ones on the same bulk like deleteOne, replaceOne, insertOne, etc.
You can check more here: https://docs.mongodb.com/manual/reference/method/db.collection.bulkWrite/
Try this for updating bulk data
const data = [
{
_id: 'dfjkldsjfkldjas',
name: 'will'
},
{
_id: 'fdsfdakjdhfaskh',
name: 'bob'
},
{
_id: 'fdsfdasfdfewrfq',
name: 'tom'
}
]
const bulkData = data.map(item => (
{
updateOne: {
filter: { _id: item._id },
update: { $set: { name: item.name } },
upsert: true
}
})
);
await db1.bulkWrite(bulkData, { ordered: false, upsert: true });
If a have a following structure :
{
_id: 1,
name: 'a',
info: []
},
{
_id: 2,
name: 'b',
info: [
{
infoID: 100,
infoData: 'my info'
}
]
},
{
_id: 3,
name: 'c',
info: [
{
infoID: 200,
infoData: 'some info 200'
},
{
infoID: 300,
infoData: 'some info 300'
}
]
}
I need to query in such a way to obtain the documents where infoID is 100 showing the infoData, or nothing if info is empty, or contains subdocuments with infoID different from 100.
That is, I would want the following output:
{
_id: 1,
name: 'a',
infoData100: null
},
{
_id: 2,
name: 'b',
infoData100: 'my info'
},
{
_id: 3,
name: 'c',
infoData100: null
}
If I $unwind by info and $match by infoID: 100, I lose records 1 and 3.
Thanks for your responses.
Try below query :
Query :
db.collection.aggregate([
/** Adding a new field or you can use $project instead of addFields */
{
$addFields: {
infoData100: {
$cond: [
{
$in: [100, "$info.infoID"] // Check if any of objects 'info.infoID' has value 100
},
{
// If any of those has get that object & get infoData & assign it to 'infoData100' field
$let: {
vars: {
data: {
$arrayElemAt: [
{
$filter: {
input: "$info",
cond: { $eq: ["$$this.infoID", 100] }
}
},
0
]
}
},
in: "$$data.infoData"
}
},
null // If none has return NULL
]
}
}
}
]);
Test : MongoDB-Playground
I have an image schema that has a reference to a category schema and a nested array that contains an object with two fields (user, createdAt)
I am trying to query the schema by a category and add two custom fields to each image in my query.
Here is the solution with virtual fields:
totalLikes: Count of all nested attributes
schema.virtual("totalLikes").get(function() {
return this.likes.length;
});
canLike: Check if user with id "5c8f9e676ed4356b1de3eaa1" is included in the nested array. If user is included it should return false otherwise true
schema.virtual("canLike").get(function() {
return !this.likes.find(like => {
return like.user === "5c8f9e676ed4356b1de3eaa1";
});
});
In sql it would be a simple SUBQUERY but I can't get it working in Mongoose.
Schema:
import mongoose from "mongoose";
const model = new mongoose.Schema(
{
category: {
type: mongoose.Schema.Types.ObjectId,
ref: "Category"
},
likes: [{
user: {
type: String,
required: true
},
createdAt: {
type: Date,
required: true
}
}]
})
here is a sample document:
[{
category:5c90a0777952597cda9e9c8d,
likes: [
{
_id: "5c90a4c79906507dac54e764",
user: "5c8f9e676ed4356b1de3eaa1",
createdAt:"2019-03-19T08:13:59.250+00:00"
}
]
},
{
category:5c90a0777952597cda9e9c8d,
likes: [
{
_id: "5c90a4c79906507dac54e764",
user: "5c8f9e676ed4356b1dw223332",
createdAt:"2019-03-19T08:13:59.250+00:00"
},
{
_id: "5c90a4c79906507dac54e764",
user: "5c8f9e676ed4356b1d8498933",
createdAt:"2019-03-19T08:13:59.250+00:00"
}
]
}]
Here is how it should look like:
[{
category:5c90a0777952597cda9e9c8d,
likes: [
{
_id: "5c90a4c79906507dac54e764",
user: "5c8f9e676ed4356b1de3eaa1",
createdAt:"2019-03-19T08:13:59.250+00:00"
}
],
totalLikes: 1,
canLike: false
},
{
category:5c90a0777952597cda9e9c8d,
likes: [
{
_id: "5c90a4c79906507dac54e764",
user: "5c8f9e676ed4356b1dw223332",
createdAt:"2019-03-19T08:13:59.250+00:00"
},
{
_id: "5c90a4c79906507dac54e764",
user: "5c8f9e676ed4356b1d8498933",
createdAt:"2019-03-19T08:13:59.250+00:00"
}
],
totalLikes: 2,
canLike: true
}]
Here is what I tried:
Resolver:
1) Tried in Mongoose call - Fails
const resources = await model.aggregate([
{ $match: {category: "5c90a0777952597cda9e9c8d"},
$addFields: {
totalLikes: {
$size: {
$filter: {
input: "$likes",
as: "el",
cond: "$$el.user"
}
}
}
},
$addFields: {
canLike: {
$match: {
'likes.user':"5c8f9e676ed4356b1de3eaa1"
}
}
}
}
])
2) Tried to change it after db call - works but not preferred solution
model.where({ competition: "5c90a0777952597cda9e9c8d" }).exec(function (err, records) {
resources = records.map(resource => {
resource.likes = resource.likes ? resource.likes: []
const included = resource.likes.find(like => {
return like.user === "5c8f9e676ed4356b1de3eaa1";
});
resource.set('totalLikes', resource.likes.length, {strict: false});
resource.set('canLike', !included, {strict: false});
return resource
});
})
Does anyone know how I can do it at runtime? THX
you can achieve it using aggregate
Model.aggregate()
.addFields({ // map likes so that it can result to array of ids
likesMap: {
$map: {
input: "$likes",
as: "like",
in: "$$like.user"
}
}
})
.addFields({ // check if the id is present in likesMap
canLike: {
$cond: [
{
$in: ["5c8f9e676ed4356b1de3eaa1", "$likesMap"]
},
true,
false
]
},
totalLikes: {
$size: "$likes"
}
})
.project({ // remove likesMap
likesMap: 0,
})
I'm newbie with MongoDB.
I have created a mapReduce on my Person collection to group cities.
db.Person.find()
[{
name: 'Bob',
addresses: [
{
street: 'Vegas Street',
neighborhood: {
name: 'Center',
city: {
name: 'Springfield'
}
}
}, {
.....
}
]
}, {
....
}]
And this is my mapReduce:
db.Person.mapReduce(function() {
for (var i = 0; i < this.address.length-1; i++) {
var address = this.address[i];
emit(address.neighborhood.city.name, 1);
}
}, function(k, v) {
return v.length;
}, { out: 'City' });
Then I use this to list my cities:
db.City.find().sort({'_id:', 1})
[{
_id: 'Springfield',
value: 3
}, {
_id: 'City B',
value: 2
}, {
...
}]
My question is about the City data, I need run the mapReduce each time I insert, update or delete on my Personcollection or it runs automatically?