I'm trying to build a filter where it should be possible to query all items selected in an array, but also to show documents where the property has not been set.
returning all specific from an array works fine with below
searchCriteria.filter1 = {
$in: array.category,
};
searchCriteria.filter2 = {
$in: array.carbrand,
};
//Then the data if fetched
const fetchedData = await Activity.find(searchCriteria)
.sort({ date: -1 })
.limit(limit)
.skip(startIndex)
.exec();
However, sometimes users have not added a category, and it's just a empty array. My goal is to get all of these empty arrays as well as the specific arrays.
so something like:
searchCriteria.filter2 = {
$in: array.carbrand OR is []
};
Any suggestions?
One way you could approach this is indeed to use the $or operator. But since $in is logically an OR for a single value, you should be able to just append [] to the list being used for comparison by the $in operator.
The approach is demonstrated in this playground example.
I believe you could adjust the code in a manner similar to this:
searchCriteria.filter2 = {
$in: [...array.carbrand, []]
};
Related
enter image description here
Let's say that we have many documents like this in the photo
I have the above schema. I want to find the document based on _id first and then push an array of values to providedServices which belongs to the _id which is inside barbers array
A little help. Can't seem to find this out!
You need to find the related arrays firstly. For this, you can use $elemMatch or write it as 'barbers._id' : {$elemMatch: parameter}' .
Here we tried to find document with filtering it's own id and barbers id. You can change the filter as you wished. It can be only search on barbers id.
Need to write your DocumentName and your parameters instead of idValue, barbersId, serviceModel.
const result = await DocumentName.findOneAndUpdate(
{
$and:
[
{_id: mongoose.Types.ObjectId(idValue)},
{'barbers': {$elemMatch: {_id: mongoose.Types.ObjectId(barbersId)}}}
]
},
{ $push: { 'barbers.$.providedServices': serviceModel } },
{ new: true })
At first, we found the related barbers array inside of all documents. Then we pushed the model inside of providedServices array into this barbers array.
I am working on a collection called Publications. Each publication has an array of objectives which are ids. I have also a custom array of objectives hand written. Now, I want to select all the publications that contains at least one element of the custom objectives array in their objectives. How can I do that ?
I've been trying to make this works with '$setIntersection' then '$count' and verify that the count is greater than 0 but I don't know how to implement this.
Example :
publication_1: {
'_id': ObjectId("sdfsdf46543")
'objectives': [ObjectId("1654351456341"), ObjectId("123456789")]
}
publication_2: {
'_id': ObjectId("sdfs216546543")
'objectives': [ObjectId("1654351456341"), ObjectId("46531132")]
}
custom_array = [ObjectId("123456789"), ObjectId("2416315463")]
The mongo query should return publication_1.
You can do like the following:
db.publications.find({
"objectives": {
"$in": [
ObjectId("123456789"),
ObjectId("2416315463")
]
}
})
Notice: "123456789" is not a valid ObjectId so the query itself may not work. Here is the working example
Mongodb playground link: https://mongoplayground.net/p/MbZK99Pd5YR
objectives is an array of objects, I guess you can just query that field directly:
let custom_array = [ObjectId("123456789"), ObjectId("2416315463")];
// You can search the array with $in property.
let result = await Model.find({ objectives: {$in : custom_array} })
I'm trying to update an array that sits inside another array in a document. The schema is like this:
const projectSchema = new mongoose.Schema({
stakeholders: [{
stakeholderTitle: {
type: String,
},
...
subgroup: [{
subgroupTitle: {
type: String
},
subgroupPercent: {
type: Number,
}
}]
}],
and I'm trying to update the 'subgroup' array. I have got the query to work on its parent (the stakeholder array) with the positional $ operator, using the answer to this question I asked previously. So my query looks like this.....
await db.findOneAndUpdate({ find by the id }, { "stakeholders.$.stakeholderTitle": req.body.stakeholderTitle, ... "stakeholders.$.subgroup": req.body.subgroup })
However, this query doesn't work for the 'stakeholders subgroup' array, and makes it null. Looking through the mongo docs for the positional operator it states that 'The positional $ operator cannot be used for queries which traverse more than one array, such as queries that traverse arrays nested within other arrays, because the replacement for the $ placeholder is a single value', which I guess might be my problem.
So how can I do this with a findOneAndUpdate query?
From what I see is you have to specify the object you want to update inside the subgroup array. Try this - (i.e I'm updating the subgroupTitle of the subgroup array);
await db.findOneAndUpdate(
{
_id: userId,
"stakeholders.stakeholderTitle": req.body.stakeholderTitle,
"stakeholders.stakeholderTitle.subgroup.subgroupTitle": req.body.subgroupTitle
},
{$set: {
"stakeholders.stakeholderTitle.subgroup.$.subgroupPercent": somePercentValue,
}
},
);
Also note, it's only the array that you find that you can update. It might not be exactly what you want, but its a step closer
Here is the data structure for each document in the collection. The datastructure is fixed.
{
'_id': 'some-timestamp',
'RESULT': [
{
'NUMERATION': [ // numeration of divisions
{
// numeration of producttypes
'DIVISIONX': [{'PRODUCTTYPE': 'product xy', COUNT: 100}]
}
]
}
]
}
The query result should be in the same structure but only contain producttypes matching a regular expression.
I tried using an nested $elemMatchoperator but this doesn't get me any closer. I don't know how I can iterate each value in the producttypes array for each division.
How can I do that? Then I could apply $pop, $in and $each.
I looked at:
Querying an array of arrays in MongoDB
https://docs.mongodb.com/manual/reference/operator/update/each/
https://docs.mongodb.com/manual/reference/operator/update/pop/
... and more
The solution I want to avoid is writing something like this:
collection.find().forEach(function(x) { /* more for eaches */ })
Edit:
Here is an example document to copy:
{"_id":"5ab550d7e85d5930b0879cbe","RESULT":[{"NUMERATION":[{"DIVISION":[{"PRODUCTTYPE":"Book","COUNT":10},{"PRODUCTTYPE":"Giftcard","COUNT":"300"}]}]}]}
E.g. the query result should only return the entry with the giftcard:
{"_id":"5ab550d7e85d5930b0879cbe","RESULT":[{"NUMERATION":[{"DIVISION":[{"PRODUCTTYPE":"Giftcard","COUNT":"300"}]}]}]}
Using the forEach approach the result is in the correct format. I'm still looking for a better way which does not involve the use of that function - therefore I will not mark this as an answer.
But for now this works fine:
db.collection.find().forEach(
function(wholeDocument) {
wholeDocument['RESULT'].forEach(function (resultEntry) {
resultEntry['NUMERATION'].forEach(function (numerationEntry) {
numerationEntry['DIVISION'].forEach(function(divisionEntry, index) {
// example condition (will be replaced by regular expression evaluation)
if(divisionEntry['PRODUCTTYPE'] != 'Giftcard'){
numerationEntry['DIVISION'].splice(index, 1);
}
})
})
})
print(wholeDocument);
}
)
UPDATE
Thanks to Rahul Raj's comments I have read up the aggregation with the $redact operator. A prototype of the solution to the issue is this query:
db.getCollection('DeepStructure').aggregate( [
{ $redact: {
$cond: {
if: { $ne: [ "$PRODUCTTYPE", "Giftcard" ] },
then: "$$DESCEND",
else: "$$PRUNE"
}
}
}
]
)
I hope you're trying to update nested array.
You need to use positional operators $[] or $ for that.
If you use $[], you will be able to remove all matching nested array elements.
And if you use $, only the first matching array element will get removed.
Use $regex operator to pass on your regular expression.
Also, you need to use $pull to remove array elements based on matching condition. In your case, its regular expression. Note that $elemMatch is not the correct one to use with $pull as arguments to $pull are direct queries to the array.
db.collection.update(
{/*additional matching conditions*/},
{$pull: {"RESULT.$[].NUMERATION.$[].DIVISIONX":{PRODUCTTYPE: {$regex: "xy"}}}},
{multi: true}
)
Just replace xy with your regular expression and add your own matching conditions as required. I'm not quite sure about your data set, but I came up with the above answer based on my assumptions from the given info. Feel free to change according to your requirements.
I have documents with the following structure:
{
...,
trials:[ {...,
ref:[{a:1,b:2},{a:2,b:2},...]
},
{...,
ref:[{a:1,b:2}]
},
...,
]
}
Where ref is an array guaranteed to be of length of at least 1.
If I want to count the individual occurrences of each of elements in each of the ref arrays I would use the following aggregation. (This works fine)
db.cl.aggregate([
{$unwind:"$trials"},
{$unwind:"$trials.ref"},
{$group:{_id:"$trials.ref", count:{$sum:1}}}
])
Now I want to do the same thing, but only with the last element in each ref array. I need a way to only select the last element of each array in the aggregation pipeline.
I first thought I could add a intermediate step to just get all the elements that I want to group by doing something like this:
db.cl.aggregate([
{$unwind:"$trials"},
{$group:{_id:null,arr:{$push:"$trials.ref.-1"}}},...
])
I've also tried using a position operator with $match.
db.cl.aggregate([
{$unwind:"$trials"},
{$match:{"trials.ref.$":-1}},...
])
Or trying to project the last element.
db.cl.aggregate([
{$unwind:"$trials"},
{$project:{ref:"$trials.ref.1"}}
])
Neither of these get me anywhere. The $pop operator is not valid in the aggregation pipeline. $last operator isn't really useful here.
Any ideas on how to only use the last element of the ref array? I'd rather keep with the aggregation framework and NOT use Map Reduce.
The aggregation framework really has no way of dealing with this. Aside from lacking any "slice" type operator, the real problem here is the lack of any marker to tell where your inner array ends, and there really isn't any way to do that with any other form of document re-shaping.
For now at least, the mapReduce approach is very simple, and does not even require a reducer:
db.cl.mapReduce(
function() {
this.trials.forEach(function(trial) {
trial.ref = trial.ref.slice(-1);
});
var id = this._id;
delete this._id;
emit( id, this );
},
function(){},
{ "out": { "inline": 1 } }
)
In the future there might be some hope. Some form of $slice has sought after for some time. But I did notice this interesting snippet inside the $map operator code. Just to list here as well:
output.reserve(input.size());
for (size_t i=0; i < input.size(); i++) {
vars->setValue(_varId, input[i]);
Value toInsert = _each->evaluateInternal(vars);
if (toInsert.missing())
toInsert = Value(BSONNULL); // can't insert missing values into array
output.push_back(toInsert);
}
Note the for loop and the index value. I for one would be voting to have this exposed as a variable within the $map operator, as where you know the current position and the length of the array you can effectively do "slicing".
But for now, there is not a way to tell where you are in the array using $map and if you $unwind both of your arrays, you loose the end-points of the inner arrays. So the aggregation framework is lacking in the solutions to the right now.