I don't know if my question was already asked, but I didn't find any.
I need to query an object using the fields from nested objects.
Let me explain this by using images.
In image 1, you can see an "object type" called dialogcontext which refers another collection in my database.
So, I know that with populate function I can get the tested object fields, but I need to create a query using those nested fields.
Something like this:
let detailWeb = await Interaction.aggregate([
{ $match: { dateAdded: { $gte: start, $lt: end } } },
{
"$group": {
_id: { "dialogcontext.channel": "Web" },
data: { $sum: 1 }
}
},
{ $sort: { _id: 1 } }]).exec();
Do you have any idea or suggestion ?
Thank you in advance.
Related
I have a collection- 'products' that contains the following documents:
{
productName: "computer",
updateAt: "2022-07-12T12:44:47.485Z",
createAt: ""2022-06-12T10:34:03.485Z",
changeAt: ""2022-09-12T10:39:40.485Z"
}
I want to create an aggregation that convert the field "updateAt" from string to date.
for this, I created this aggregation:
db.products.aggregate([{
$set: {
updateAt: {
$dateFromString: {
dateString: '$updateAt'
}
}
},
},
{
$out: 'products'
}]
)
It works fine for this need, but as you can see I specified the field path "updateAt" in a hard coded way.I want to use the above aggregation in a dynamic way-
considering I have an array of fields that I want to change:
const fields = ['updateAt', 'createAt', 'changeAt']
I want to loop over the fields array and use each field as a fieldPath so I can transfer the field name to the aggregation, something like that-
fields.forEech(field -> {
db.products.aggregate([{
$set: {
`${field}`: {
$dateFromString: {
dateString: `$${field}`
}
}
},
},
{
$out: 'products'
}]
)
}
As you can understand it's not working for me....
How can I achieve my goal?
You have some errors in your nodejs function, also, aggregate method returns a Promise, so you will need to wait for it, to resolve before moving further.
Try this:
const fields = ['updateAt', 'createAt', 'changeAt']
for(let i=0; i < fields.length; i++) {
let field = fields[i];
await db.products.aggregate([{
"$set": {
[field]: {
"$dateFromString": {
"dateString": `$${field}`
}
}
},
},
{
"$out": 'products'
}]
)
}
Also, make the function containing this piece of code async.
I'd like to do a search in MongoDB using either Mongo or Mongoose based on the value of a field in a document.
Let's say I had three MongoDB documents that looked like this:
{
name: "Michael",
mentored: ["Dwight", "Ryan", "Jim"]
},
{
name: "Jim",
mentored: ["Toby", "Roy", "Darryl"]
},
{
name: "Stanley",
mentored: ["Pam", "Meredith", "Angela"]
}
Let's further say I want to do a search for anyone who Michael has not mentored, which in this case would be Stanley (let's assume that the people in the arrays don't necessarily have their own records). I know I can do a search like this in Mongoose to get the result I want:
User.findOne({ name: "Michael" })
.then((person) => {
const mentored = person.mentored
return User.find({ name: { $nin: mentored } })
)
.then((person2) => {
console.log(person2); // Stanley
})
However, is there any way to do this without first returning the array from the database and then doing a second search? Something like this:
User.findOne({ name: { $nin: { "Michael's mentored people array" } } })
Ultimately I'm looking to see if there's any way to make more efficient such a situation in which arrays can get 10s of thousands of values long. Many thanks.
I think what you are doing is already efficient for large arrays.
But you could try the following, as suggested by #D.SM. but using aggregation the intermediate results will have to be loaded in memory, which does not seem efficient to me.
User.aggregate([
{
$match: {
name: "Michael"
}
},
{
$lookup: {
from: "collection",
as: "notMentored",
let: {
mentored: "$mentored",
/*
You probably want to remove "Michael" from the result, one way is to add him to the mentored array
mentored: { $concatArrays: ["$mentored", ["$name"]]}
*/
},
pipeline: [{
$match: {
$expr: { $not: { $in: ["$name", "$$mentored"] } }
}
}]
}
},
{
$unwind: "$notMentored"
},
{
$replaceRoot: {
newRoot: "$notMentored"
}
}
])
I'm trying to make trivial SUM on mongoDB to count number of prices for single client.
My collection:
{"_id":"5d973c71dd93adfbda4c7272","name":"Faktura2019006","clientId":"5d9c87a6b9676069c8b5e15b","expiration":"2019-10-02T01:11:18.965Z","price":999999,"userId":"123"},
{"_id":"5d9e07e0b9676069c8b5e15d","name":"Faktura2019007","clientId":"5d9c87a6b9676069c8b5e15b","expiration":"2019-10-02T01:11:18.965Z","price":888,"userId":"123"}
What I tried:
// invoice.model.js
const mongoose = require("mongoose");
const InvoiceSchema = mongoose.Schema({
_id: String,
name: String,
client: String,
userId: String,
expiration: Date,
price: Number
});
module.exports = mongoose.model("Invoice", InvoiceSchema, "invoice");
and
// invoice.controller.js
const Invoice = require("../models/invoice.model.js");
exports.income = (req, res) => {
console.log("Counting Income");
Invoice.aggregate([
{
$match: {
userId: "123"
}
},
{
$group: {
total: { $sum: ["$price"] }
}
}
]);
};
What happen:
When I now open a browser and code above is being called, I get console log 'Counting Income' in terminal however in browser it's just loading forever and nothing happen.
Most likely I just miss some stupid minor thing but I'm trying to find it out for quite a long time without any success so any advise is welcome.
The reason that the controller never finishes is because you are not ending the response process (meaning, you need to use the res object and send something back to the caller).
In order to get the aggregate value, you also need to execute the pipeline (see this example).
Also, as someone pointed out in the comments, you need to add _id: null in your group to specify that you are not going to group by any specific field (see the second example here).
Finally, in the $sum operator, for what you're trying to do, you just need to remove the array brackets since you only want to sum on a single field (see a few examples down here).
Here is the modified code:
// invoice.controller.js
const Invoice = require("../models/invoice.model.js");
exports.income = (req, res) => {
console.log("Counting Income");
Invoice.aggregate([
{
$match: {
userId: "123"
}
},
{
$group: {
_id: null,
total: { $sum: "$price" }
}
}
]).then((response) => {
res.json(response);
});
};
Edit for your comment about when an empty array is returned.
If you want to always return the same type of object, I would control that in the controller. I'm not sure if there is a fancy way to do this with the aggregate pipeline in mongo, but this is what I would do.
Invoice.aggregate([
{
$match: {
userId: "123"
}
},
{
$group: {
_id: null,
total: { $sum: "$price" }
}
},
{
$project: {
_id: 0,
total: "$total"
}
}
]).then((response) => {
if (response.length === 0) {
res.json({ total: 0 });
} else {
// always return the first (and only) value
res.json(response[0]);
}
});
Here, if you find a userId of 123, then you would get this as the return:
{
"total": 1000887
}
But if you change the userId to, say, 1123 which doesn't exist in your db, the result will be:
{
"total": 0
}
This way, your client can always consume the same type of object.
Also, the reason I put the $project pipeline stage in there was to suppress the _id field (see here for more info).
I post this question in relation to my use case.
It is true that there is a lot of response in the same subject but I do not find an answer .
that is why I ask you for help Thanks.
I would like to be able to update the lineItemStatus inside lineItems array.
Here is my model :
const orderSchema = new Schema(
lineItems: [{
lineItemStatus: {
type: String,
default: 'en waiting for validation',
lowercase: true
}
}]
)
The result look like this
{
"_id": "5c659cd0be79c124126d5ec2",
"lineItems": [{
"lineItemStatus": "waiting for validation", //the status to update
"_id": "1"
},
{
"lineItemStatus": "delivered",
"_id": "2"
}
]
}
First I'm able to get a single item of lineItems.
this is the code
async updateStatus(req, res) {
let givenLineItemId = req.body.lineItemId
let givenlineItemStatus = req.body.status // the status to update
try {
const ObjectId = mongoose.Types.ObjectId
const aggregationStages = [
{
$unwind: '$lineItems'
},
{
$match: {
'lineItems._id': ObjectId(givenLineItemId)
}
}
]
await Order
.aggregate(aggregationStages)
.exec(function(err, orders) {
if (err) res.status(400).send(err)
res.status(200).send(orders)
})
} catch (err) {
return res.status(500).send(err)
}
}
But now i'm not able to to update the lineItemStatus i see some way to use set or push but it doesn't work.
Thanks a lot for the help.
The aggregation stage itself does not support updates. You have two options:
1) Collect the aggregate results into a variable and do a bulk update. See link.
2) Call forEach on the aggregate. You can see samples provided in this answer.
I have the following mongodb query in node.js which gives me a list of unique zip codes with a count of how many times the zip code appears in the database.
collection.aggregate( [
{
$group: {
_id: "$Location.Zip",
count: { $sum: 1 }
}
},
{ $sort: { _id: 1 } },
{ $match: { count: { $gt: 1 } } }
], function ( lookupErr, lookupData ) {
if (lookupErr) {
res.send(lookupErr);
return;
}
res.send(lookupData.sort());
});
});
How can this query be modified to return one specific zip code? I've tried the condition clause but have not been able to get it to work.
Aggregations that require filtered results can be done with the $match operator. Without tweaking what you already have, I would suggest just sticking in a $match for the zip code you want returned at the top of the aggregation list.
collection.aggregate( [
{
$match: {
zip: 47421
}
},
{
$group: {
...
This example will result in every aggregation operation after the $match working on only the data set that is returned by the $match of the zip key to the value 47421.
in the $match pipeline operator add
{ $match: { count: { $gt: 1 },
_id : "10002" //replace 10002 with the zip code you want
}}
As a side note, you should put the $match operator first and in general as high in the aggregation chain as you can.