I have the following schema:
{
_id: objectID('593f8c591aa95154cfebe612'),
name: 'test'
businesses: [
{
_id: objectID('5967bd5f1aa9515fd9cdc87f'),
likes: [objectID('595796811aa9514c862033a1'), objectID('593f8c591ba95154cfebe790')]
}
{
_id: objectID('59579ff91aa9514f600cbba6'),
likes: [objectID('693f8c554aa95154cfebe146'), objectID('193f8c591ba95154cfeber790')]
}
]
}
I need to update "businesses.likes" where businesses._id equal to a center value and where businesses.likes contains certain objectID.
If the objectID exists in the array, I want to remove it.
This is what I have tried and didn't work correctly, because $in is searching in all the subdocuments, instead of the only subdocument where businesses._id = with my value:
db.col.update(
{ businesses._id: objectID('5967bd5f1aa9515fd9cdc87f'), 'businesses.likes': {$in: [objectID('193f8c591ba95154cfeber790')]}},
{$pull: {'businesses.$.likes': objectID('193f8c591ba95154cfeber790')}}
)
Any ideas how how I can write the query? Keep in mind that businesses.likes from different businesses can have the same objectID's.
Related
This has been extensively covered here, but none of the solutions seems to be working for me. I'm attempting to remove an object from an array using that object's id. Currently, my Schema is:
const scheduleSchema = new Schema({
//unrelated
_id: ObjectId
shifts: [
{
_id: Types.ObjectId,
name: String,
shift_start: Date,
shift_end: Date,
},
],
});
I've tried almost every variation of something like this:
.findOneAndUpdate(
{ _id: req.params.id },
{
$pull: {
shifts: { _id: new Types.ObjectId(req.params.id) },
},
}
);
Database:
Database Format
Within these variations, the usual response I've gotten has been either an empty array or null.
I was able slightly find a way around this and accomplish the deletion by utilizing the main _id of the Schema (instead of the nested one:
.findOneAndUpdate(
{ _id: <main _id> },
{ $pull: { shifts: { _id: new Types.ObjectId(<nested _id>) } } },
{ new: true }
);
But I was hoping to figure out a way to do this by just using the nested _id. Any suggestions?
The problem you are having currently is you are using the same _id.
Using mongo, update method allows three objects: query, update and options.
query object is the object into collection which will be updated.
update is the action to do into the object (add, change value...).
options different options to add.
Then, assuming you have this collection:
[
{
"_id": 1,
"shifts": [
{
"_id": 2
},
{
"_id": 3
}
]
}
]
If you try to look for a document which _id is 2, obviously response will be empty (example).
Then, if none document has been found, none document will be updated.
What happens if we look for a document using shifts._id:2?
This tells mongo "search a document where shifts field has an object with _id equals to 2". This query works ok (example) but be careful, this returns the WHOLE document, not only the array which match the _id.
This not return:
[
{
"_id": 1,
"shifts": [
{
"_id": 2
}
]
}
]
Using this query mongo returns the ENTIRE document where exists a field called shifts that contains an object with an _id with value 2. This also include the whole array.
So, with tat, you know why find object works. Now adding this to an update query you can create the query:
This one to remove all shifts._id which are equal to 2.
db.collection.update({
"shifts._id": 2
},
{
$pull: {
shifts: {
_id: 2
}
}
})
Example
Or this one to remove shifts._id if parent _id is equal to 1
db.collection.update({
"_id": 1
},
{
$pull: {
shifts: {
_id: 2
}
}
})
Example
I have a document model that contains an array of user objects. What I want to do is return the document if that array contains an object with a specific user _id. Is this possible?
Something like
{
_id: 1
name: 'Document with Array of User Ids'
arrayOfUsers: [
{
name: 'John Doe',
_id: 2
},
{
name: 'Michael Scott',
_id: 3
}
]
}
And then returning all documents that have an _id of 3 in arrayOfUsers
Thanks!
You can use dot notation like so:
https://mongoplayground.net/p/iu0f68D1vbL
Model.find({
"arrayOfUsers._id": 2
})
https://docs.mongodb.com/manual/tutorial/query-embedded-documents/#query-on-nested-field
Suppose I have the following schema:
{
_id: ObjectId(1),
title: string,
answers: [
{
_id: ObjectId(2),
text: string,
upVotes: [
{
_id: ObjectId(3),
userId: ObjectId(4)
}
]
}
]
}
What I want is pull vote of a specific user from answer upvotes, and return the new update result.
For example, find a question with id 1, and get its specific answer with id 2, then from that answer pull my vote using userId inside upvotes.
I want to do it with a single findOneAndUpdate query
You can even use single $ positional with the $pull operator to update the nested array
db.collection.findOneAndUpdate(
{ "_id": ObjectId(1), "answers._id": ObjectId(2) },
{ "$pull": { "answers.$.upVotes": { "userId": ObjectId(4) }}}
)
I think I understood that you want to do a search in the specific array
db.collection.update(
{
"_id": "507f1f77bcf86cd799439011", // id field
"answers.upVotes._id":"507f1f77bcf86cd799439011" //id array
}
),{
"$set":{"answers.$.upVotes": {userId :"507f1f77bcf86cd799439011"}}},//edit
//use "addToSet" for add
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)
Suppose, I have the following database:
{
_id: 1,
name: 'Alice',
courses: [
{
_id: 'DB103',
credits: 6
},
{
_id: 'ML203',
credits: 4
}
]
},
{
_id: 2,
name: 'Bob',
courses: []
}
I now want to 'upsert' the document with the course id 'DB103' in both documents. Although the _id field should remain the same, the credits field value should change (i.e. to 4). In the first document, the respective field should be changed, in the second one, {_id: 'DB103', credits: 4} should be inserted into the courses array.
Is there any possibility in MongoDB to handle both cases?
Sure, I could search with $elemMatch in courses for 'DB103' and if I haven't found it, insert, otherwise update the value. But these are two steps and I would like to do both in just one.