I need to perform a query that returns all results where an id, or array of ids in an array of ids AND another id, or array of ids, is in another array of ids. Perhaps an example will better explain what I'm trying to do:
Schema:
var somethingSchema = mongoose.Schema({
space_id : String,
title : String,
created : {
type: Date,
default: Date.now
},
visibility : {
groups : [{
type : String,
ref : 'Groups'
}],
users : [{
type : String,
ref : 'User'
}]
}
});
Query:
something.find({
space_id: req.user.space_id,
$and: [
{ $or: [{ "visibility.groups": { $in: groups } }] },
{ $or: [{ "visibility.users": { $in: users } }] }
]
}, function (err, data) {
return res.json(data);
});
In this example, both groups and users are arrays of ids. The query above isn't working. It always returns an empty array. What am I doing wrong?
You should be including all clauses to OR together in a single $or array:
something.find({
space_id: req.user.space_id,
$or: [{ "visibility.groups": { $in: groups } },
{ "visibility.users": { $in: users } }]
}, function (err, data) {
return res.json(data);
});
Which translates to: find all docs with a matching space_id AND that have a visibility.groups value in groups OR a visibility.users value in users.
Related
So I have a questionnaire model:
const schema = new mongoose.Schema({
title: String,
category: String,
description: String,
requirementOption: String,
creationDate: String,
questions: [],
answers: []
})
As you can see the answers is an array. This array contains object that have this structure
{
"participantEmail": "someEmail#email.email"
"currentIndex": 14,
...
}
Now I want to get a specific questionnaire by id, but in answers array I only want specific participant email. So the answers array should have either one element or no element. But I don't want to get null result if there is no such email in the answers array.
I figure it out how to get that specific element from array with this query:
dbModel.findOne({_id: id, 'answers': {$elemMatch: {participantEmail: "someEmail#email.com"}}}, {'answers.$': 1}).exec();
And if that email exists in the answer array I will get this:
"data": {
"questionnaireForParticipant": {
"id": "5d9ca298cba039001b916c55",
"title": null,
"category": null,
"creationDate": null,
"description": null,
"questions": null,
"answers": [
{
"participantEmail": "someEmail#email.com",
....
}
}
}
But if that email is not in the answers array I will get only null. Also I would like to get the title and category and all of the other fields. But I can't seem to find a way to do this.
Since you've this condition 'answers': {$elemMatch: {participantEmail: "someEmail#email.com"}} in filter part of .findOne() - If for given _id document there are no elements in answers. participantEmail array match with input value "someEmail#email.com" then .findOne() will return null as output. So if you wanted to return document irrespective of a matching element exists in answers array or not then try below query :
db.collection.aggregate([
{
$match: { "_id": ObjectId("5a934e000102030405000000") }
},
/** addFields will re-create an existing field or will create new field if there is no field with same name */
{
$addFields: {
answers: {
$filter: { // filter will result in either [] or array with matching elements
input: "$answers",
cond: { $eq: [ "$$this.participantEmail", "someEmail#email.com" ] }
}
}
}
}
])
Test : mongoplayground
Ref : aggregation-pipeline
Note : We've used aggregation as you wanted to return either answers array with matched element or an empty array. Also you can use $project instead of $addFields to transform the output as you wanted to.
The accepted answer is correct, but if you are using mongoose like I do this is how you have to write the accepted answer query:
dbModel.aggregate([
{
$match: { "_id": mongoose.Types.ObjectId("5a934e000102030405000000") }
}]).addFields({
answers: {
$filter: {
input: "$answers",
cond: { $eq: [ "$$this.participantEmail", "someEmail#email.com" ] }
}
}
}).exec();
With this sample input document:
{
_id: 1,
title: "t-1",
category: "cat-abc",
creationDate: ISODate("2020-05-05T07:01:09.853Z"),
questions: [ ],
answers: [
{ participantEmail: "someEmail#email.email", currentIndex: 14 }
]
}
And, with this query:
EMAIL_TO_MATCH = "someEmail#email.email"
db.questionnaire.findOne(
{ _id: 1 },
{ title: 1, category: 1, answers: { $elemMatch: { participantEmail: EMAIL_TO_MATCH } } }
)
The query returns (when the answers.participantEmail matches):
{
"_id" : 1,
"title" : "t-1",
"category" : "cat-abc",
"answers" : [
{
"participantEmail" : "someEmail#email.email",
"currentIndex" : 12
}
]
}
And, when the answers.participantEmail doesn't match or if the amswers array is empty, the result is:
{ "_id" : 1, "title" : "t-1", "category" : "cat-abc" }
NOTE: The $elemMatch used in the above query is a projection operator.
How do I update an item in the parent document and upsert a subdocument in a single query?
This is my example schema.
const ExampleSchema = new Schema({
user_count: {
type: String,
default: 0
},
users: [
{
id: {
type: Schema.Types.ObjectId,
ref: "users",
unique: true
},
action: {
type: Boolean
}
}
],
});
I am trying to add +1 to user_count and upsert a document to the users array in a single query.
const result = await Example.updateOne(
{
_id: id,
},
{
$set: {
"user_count": user_count++,
"users.$.id": req.user.id,
"users.$.action": true
}
},
{ upsert: true }
);
I have tried the above code, but got the following error.
[0] 'The positional operator did not find the match needed from the query.',
[0] [Symbol(mongoErrorContextSymbol)]: {} }
I'm not familiar with mongoose, so I will take for granted that "user_count": user_count++ works.
For the rest, there are two things that won't work:
the $ operator in "users.$.id": req.user.id, is known as the positional operator, and that's not what you want, it's used to update a specific element in an array. Further reading here: https://docs.mongodb.com/manual/reference/operator/update/positional/
the upsert is about inserting a full document if the update does not match anything in the collection. In your case you just want to push an element in the array right?
In this case I guess something like this might work:
const result = await Example.updateOne(
{
_id: id,
},
{
$set: {
"user_count": user_count++
},
$addToSet: {
"users": {
"id": req.user.id,
"action": true
}
}
}
);
Please note that $push might also do the trick instead of $addToSet. But $addToSet takes care of keeping stuff unique in your array.
db.collection.findOneAndUpdate({_id: id}, {$set: {"user_count": user_count++},$addToSet: {"users": {"id": req.user.id,"action": true}}}, {returnOriginal:false}, (err, doc) => {
if (err) {
console.log("Something wrong when updating data!");
}
console.log(doc);
});
At this moment I am using 2 queries to search for a username value inside a field that is an object that contains 2 arrays then merging them together. I can't seem to figure out how to write a query that would search through both arrays at once and return all results that match a given username in any of the arrays. I was wondering if this is even possible? Thanks for any inputs!
Game.find({
active: false,
'current_players.team1': { $elemMatch: { $in: [username] } }
})
Game.find({
active: false,
'current_players.team2': { $elemMatch: { $in: [username] } }
})
This is the schema I am working with:
var Game = mongoose.Schema({
id: ...,
...,
...,
current_players: {
team1: Array // [ 'jim', 'bob', 'sarah', null ]
team2: Array // [ 'peter', 'frank', null, 'simon']
}
})
To search both arrays in one query for this problem you can use the $or operator.
db.collection.find({
"active": false,
$or: [
{
"current_players.team1": "username"
},
{
"current_players.team2": "username"
}
]
})
This is how I check if a document exists:
var query = {};
if (req.body.id) {
query._id = {
$ne: new require('mongodb').ObjectID.createFromHexString(req.body.id)
};
}
Creditor.native(function(err, collection) {
collection.find({
$or: [{
name: req.body.name
}, {
sapId: req.body.sapId
},
query
]
}).limit(-1).toArray(function(err, creditors) {
if (creditors.length > 0) {
return res.send(JSON.stringify({
'message': 'creditor_exists'
}), 409);
} else {
return next();
}
})
});
To avoid that multiple documents exist with the same name or/and the same sapID I do this check on every creation/update of a document.
E.g. I want to update this document and give it a different name
{
name: 'Foo',
sapId: 123456,
id: '541ab60f07a955f447a315e4'
}
But when I log the creditors variable I get this:
[{
_id: 541a89a9bcf55f5a45c6b648,
name: 'Bar',
sapId: 3454345
}]
But the query should only match the same sapID/name. However there totally not the same. Is my query wrong?
You're currently finding docs where name matches OR sapId matches OR _id doesn't match. So that last clause is what's pulling in the doc you're seeing.
You probably mean to find docs where (name matches OR sapId matches) AND _id doesn't match.
collection.find({ $and: [
query,
{ $or: [{
name: req.body.name
}, {
sapId: req.body.sapId
}
] } ]
})
Or more simply:
collection.find({
_id: { $ne: require('mongodb').ObjectID.createFromHexString(req.body.id) },
$or: [{
name: req.body.name
}, {
sapId: req.body.sapId
}
]
})
Let's say I have a simple schema:
var testSchema = new mongoose.Schema({
map: { type: [ mongoose.Schema.Types.Mixed ], default: [] },
...possibly something else
});
Now let's ensure that pairs (_id, map._id) are unique.
testSchema.index({ _id: 1, 'map._id': 1 }, { unique: true });
Quick check using db.test.getIndexes() shows that it was created.
{
"v" : 1,
"unique" : true,
"key" : {
"_id" : 1,
"map._id" : 1
},
"name" : "_id_1_map._id_1",
"ns" : "test.test",
"background" : true,
"safe" : null
}
The problem is, this index is ignored and I can easily create multiple subdocuments with the same map._id. I can easily execute following query multiple times:
db.maps.update({ _id: ObjectId("some valid id") }, { $push: { map: { '_id': 'asd' } } });
and end up with following:
{
"_id": ObjectId("some valid id"),
"map": [
{
"_id": "asd"
},
{
"_id": "asd"
},
{
"_id": "asd"
}
]
}
What's going on here? Why can I push conflicting subdocuments?
Long story short: Mongo doesn't support unique indexes for subdocuments, although it allows creating them...
This comes up in google so I thought I'd add an alternative to using an index to achieve unique key constraint like functionality in subdocuments, hope that's OK.
I'm not terribly familiar with Mongoose so it's just a mongo console update:
var foo = { _id: 'some value' }; //Your new subdoc here
db.yourCollection.update(
{ '_id': 'your query here', 'myArray._id': { '$ne': foo._id } },
{ '$push': { myArray: { foo } })
With documents looking like:
{
_id: '...',
myArray: [{_id:'your schema here'}, {...}, ...]
}
The key being that you ensure update will not return a document to update (i.e. the find part) if your subdocument key already exists.
First objectId length in mongodb must be 24. Then you can turn off _id, and rename _id as id or others,and try $addToSet. Good luck.
CoffeeScript example:
FromSchema = new Schema(
source: { type: String, trim: true }
version: String
{ _id: false }//to trun off _id
)
VisitorSchema = new Schema(
id: { type: String, unique: true, trim: true }
uids: [ { type: Number, unique: true} ]
from: [ FromSchema ]
)
//to update
Visitor.findOneAndUpdate(
{ id: idfa }
{ $addToSet: { uids: uid, from: { source: source, version: version } } }
{ upsert: true }
(err, visitor) ->
//do stuff