I have an array of Tags in my Post schema:
tags: [ { type: Schema.Types.ObjectId, ref: 'Tag' } ],
Tag looks like this:
{ name: String }
When I populate the tags array it is of course populated with tag object literals.
Is there a way I can instead have mongoose populate the array with only the name string from the tag?
I have tried only specifying the name, but then name is returned within an object literal.
Currently the population outputs:
[ { name: 'React' }, { name: 'JavaScript' } ]
But I would like it to be:
[ 'React', 'JavaScript']
Is there a way to do this with Mongoose ?
You can make use of 'post' Query Middleware function. This function will be triggered before the actual data is returned by Model.find() or Model.findOne() query. Inside the function you can use Array.map to transform the data to required format.
schema.post('findOne', function(doc) {
// Transform the doc here.
// Example:
// doc.tags = doc.tags.map(tag => tag.name);
});
You could also do the same for handling Model.find().
schema.post('find', function(docs) {
// Transform the doc here.
// Example:
// docs = docs.map(doc => {
// doc.tags = doc.tags.map(tag => tag.name);
// return doc;
// });
});
You can use a virtual that returns a reduction of the tags array:
schema.virtual('plainTags').get(function () {
// first, validate if the 'tags' path is populated
if (!this.populated('tags')) {
return this.tags
}
return this.tags.reduce(function(col, Tag) {
col.push(Tag.name) return col
}, [])
})
Related
I have a Node.js program that is using Mongo Atlas search indexes and is utilizing the Aggregate function inside of the MongoDB driver. In order to search, the user would pass the search queries inside of the query parameters of the URL. That being said, I am trying to build a search object based on if a query parameter exists or not. In order to build the search object I am currently using object spread syntax and parameter short-circuiting, like so:
const mustObj = {
...(query.term && {
text: {
query: query.term,
path: ['name', 'description', 'specs'],
fuzzy: {
maxEdits: 2.0,
},
},
})
}
This is a shortened version, as there are many more parameters, but you get the jest.
In a MongoDB search query, if you have multiple parameters that must meet a certain criteria, they have to be included inside of an array called must, like so:
{
$search: {
compound: {
must: [],
},
},
}
So, in order to include my search params I must first turn my mustObj into an array of objects using Object.keys and mapping them to an array, then assigning the searches 'must' array to the array I've created, like so:
const mustArr = Object.keys(mustObj).map((key) => {
return { [key === 'text2' ? 'text' : key]: mustObj[key] };
});
searchObj[0].$search.compound.must = mustArr;
What I would like to do is, instead of creating the mustObj and then looping over the entire thing to create an array, is to just create the array using the spread syntax and short-curcuiting method I used when creating the object.
I've tried the below code, but to no avail. I get the 'object is not iterable' error:
const mustArr = [
...(query.term && {
text: {
query: query.term,
path: ['name', 'description', 'specs'],
fuzzy: {
maxEdits: 2.0,
},
},
})
]
In all, my question is, is what I'm asking even possible? And if so, how?
Corrected based on #VLAZ comment:
while spread with array [...(item)], item has to be array (iterable).
When you use short-circuit, the item as below,
true && [] ==> will be `[]` ==> it will work
false && [] ==> will be `false` ==> wont work (because false is not array)
try some thing like (Similar to #Chau's suggestion)
const mustArr = [
...(query.term ? [{
text: {
query: query.term,
path: ['name', 'description', 'specs'],
fuzzy: {
maxEdits: 2.0,
},
},
}] : [])
]
When i fetch new alerts, i want to check if the ID of the new alert was already recorded. The issue is that that ID is nested inside an array. There's the alertsDetails array, which contains objects and those objects have an _ID filed which is what i want to check. I am not sure how to achieve that. I got the code below but then i have to iterate over the result to check the exists value. Im sure there must be a better way.
const mongoose = require('mongoose');
const { Schema } = mongoose;
const G2AlertsSchema = new Schema(
{
status: { type: String, required: true },
openDate: { type: Date, required: true },
alertType: { type: Array, required: true },
severity: { type: Array, required: true },
locationName: { type: Array, required: true },
history: { type: Array, required: true },
alertDetails: { type: Array, required: false },
assignedTo: { type: Schema.Types.ObjectId, ref: 'user' },
},
{
timestamps: true,
},
);
const G2Alerts = mongoose.model('G2Alert', G2AlertsSchema);
module.exports = G2Alerts;
This is the code i found on mongodb's website. I just want to see if the ID exists only. Basically when i fetch the new alerts i get an array and i iterate over it, i want to check each item's ID against what's inside the Database. If it's there, skip and go to the next. If it's new, then create a new alert and save it.
const exists = await G2Alerts.aggregate([
{
$project: {
exists: {
$in: ['5f0b4f508bda3805754ab343', '$alertDetails._id'],
},
},
},
]);
EDIT: Another thing. I am getting a eslint warning saying i should use array iteration instead of a for loop. The issue is, i need to use await when looking up the Alert ID. If i use, reduce or filter, i can't use await. If i use async inside the reduce or filter function, then it will return promises in or just an empty array.
This below works, based on the answer provided by Tom Slabbaert
const newAlertsData = [];
for (let item of alertData.data.items) {
const exists = await G2Alerts.find({ 'alertDetails._id': `${item._id}` });
if (exists.length === 0) {
newAlertsData.push(item);
}
}
if (newAlertsData.length !== 0) {......
But this does not
const filteredAlerts = alertData.data.items.reduce((filtered, item) => {
const exists = await G2Alerts.find({ 'alertDetails._id': `${item._id}` });
if (exists.length === 0) {
filtered.push(item);
}
return filtered;
}, []);
You're not far off, here is an example using the correct syntax:
const exists = await G2Alerts.findOne({"alertDetails._id": '5f0b4f508bda3805754ab343'}});
if (!exists) {
... do something
}
This can also be achieve using aggregate with a $match stage instead of a $project stage or even better countDocuments which just returns the count instead of the entire object if you do not require it.
One more thing I'd like to add is that make sure alertDetails._id is string type as you're using string in you're $in. otherwise you'll need to cast them to ObjectId type in mongoose like so:
new mongoose.Types.ObjectId('5f0b4f508bda3805754ab343')
And for Mongo:
import {ObjectId} from "mongodb"
...
new ObjectId('5f0b4f508bda3805754ab343')
EDIT
Try something like this?
let ids = alertData.data.items.map(item => item._id.toString());
let existing = await G2Alerts.distinct("alertsDetails._id", {"alertsDetails._id": {$in: ids}});
const filteredAlerts = alertData.data.items.reduce((filtered, item) => {
if (!existing.includes(item._id.toString())) {
return [item].concat(filtered)
}
return filtered;
}, []);
This way you only need to call the db once and not multiple times.
Final code based on the provided answer.
const ids = alertData.data.items.map(item => item._id);
const existing = await G2Alerts.find({ 'alertDetails._id': { $in: ids } }).distinct(
'alertDetails._id',
(err, alerts) => {
if (err) {
res.send(err);
}
return alerts;
},
);
const filteredAlerts = alertData.data.items.reduce((filtered, item) => {
if (!existing.includes(item._id.toString()) && item.openDate > dateLimit) {
return [item].concat(filtered);
}
return filtered;
}, []);
I am currently using array filters to update the nested object.
My structure is -
Category Collection -
{
name:Disease,
_id:ObjectId,
subCategory:[{
name:Hair Problems,
_id:ObjectId,
subSubCategory:[{
name: Hair Fall,
_id:ObjectId
},{
name: Dandruff,
_id:ObjectId
}]
}]
}
I want to update the subsubcategory with id 1.1.1 which I am doing by using array filters.
let query = { 'subCategories.subSubCategories._id': subSubId };
let update = { $set: { 'subCategories.$.subSubCategories.$[j]': data } };
let option = { arrayFilters: [{ 'j._id': subSubId }], new: true };
await Categories.findOneAndUpdate(query, update, option
This code is working fine but array filters change the object id of subsubCategory. Is there any other alternative to do so without changing the ObjectId.
Thanks in advance
You can loop over the keys which you are getting as payload and put inside the $set operator.
const data = {
firstKey: "key",
secondKey: "key2",
thirdKey: "key3"
}
const object = {}
for (var key in data) {
object[`subCategories.$.subSubCategories.$[j].${key}`] = data[key]
}
let query = { 'subCategories.subSubCategories._id': subSubId };
let update = { '$set': object };
let option = { 'arrayFilters': [{ 'j._id': subSubId }], 'new': true };
await Categories.findOneAndUpdate(query, update, option)
Problem is in $set line there you have not mentioned specific fields to be update instead subCategory.$.subSubCategory.$[j] will replace complete object element that matches the _id filter. Hence your _id field is also getting updated. You have to explicitly mention the field name after array element identifier. See example below:
Suppose you want to update name field in subSubCategories from Dandruff to new Dandruff. Then do this way:
let update = { $set: { 'subCategories.$.subSubCategories.$[j].name': "new Dandruff" } };
This will only update name field in subSubCategories array
So my call returns something like:
data:
{
nameData: 'Test33333',
emailData: email#email.com,
urlLink: link.com
additionalDetails: [
{
field: 'email',
value: 'other#email.com'
},
{
field: 'name',
value: 'name1223'
}
]
}
Now, I want to make a function that would take the passed parameter (data) and make an array of objects, that should look like below. It should be done in more generic way.
Array output expectation:
fullData = [
{
name: 'data_name'
value: 'Test33333'
},
{
name: 'data_email',
value: 'email#email.com'
},
{
name: 'data_url',
value: 'Link.com'
},
extraData: [
//we never know which one will it return
]
];
It should be done in the function, with name, for example:
generateDataFromObj(data)
so
generateDataArrFromObj = (data) => {
//logic here that will map correctly the data
}
How can this be achieved? I am not really proficient with JavaScript, thanks.
Assuming that you keep your data property keys in camelCase this will work for any data you add, not just the data in the example. Here I've used planetLink. It reduces over the object keys using an initial empty array), extracts the new key name from the existing property key, and concatenates each new object to the returned array.
const data = { nameData: 'Test33333', emailData: 'email#email.com', planetLink: 'Mars' };
function generateDataArrFromObj(data) {
const regex = /([a-z]+)[A-Z]/;
// `reduce` over the object keys
return Object.keys(data).reduce((acc, c) => {
// match against the lowercase part of the key value
// and create the new key name `data_x`
const key = `data_${c.match(regex)[1]}`;
return acc.concat({ name: key, value: data[c] });
}, []);
}
console.log(generateDataArrFromObj(data));
Just run a map over the object keys, this will return an array populated by each item, then in the func map runs over each item, build an object like so:
Object.keys(myObj).map(key => {return {name: key, value: myObj[key]}})
I have 2 collections.
ItemList = new Mongo.Collection('items');
BorrowerDetails = new Mongo.Collection('borrow');
ItemList.insert({
brand: "brand-Name",
type: "brand-Type",
._id: id
});
BorrowerDetails.insert({
key: "ItemList.id", //equals to .id of the ItemList Collection
name : "borrowerName"
});
Question !
How can i retrieve records from the BorrowerDetails Collection based on a certain type from the ItemList Collection.
ex. Retrieve all records from the BorrowerDetails Collection where key is equals to the id of a record on the ItemList Collection whose type is equals to "Desktop".
return BorrowerDetails.find(
{ key :
ItemList.find(
{ type : 'Desktop' },
{ fields: {'_id':1 } }
)
}
); //error!
Note that I don't have nodejs right now in my laptop, so might have several errors since I am not able to test it.
First, Create a publication file (eg. server\publications\borrowPub.js). inside the file, you should create a publication method. The logic here is simple, get the itemid array first, and then pass it as parameter in Mongo select $in.
Meteor.publish('queryBorrowerTypeDesktop', function(criteria)
{
var itemArr = ItemList.find( { type : 'Desktop' },
{ fields: {'_id':1 } });
if(itemArr){
//itemArr found, so do a select in using the array of item id we retrieved earlier
var borrowers = BorrowerDetails.find({ key: { $in: itemArr } });
return borrowers;
}else{
//found nothing- so return nothing
return []
}
});
Second, in the router :
Router.route('/test', {
name: 'test',
action: function()
{
//change accordingly.
},
waitOn: function()
{//subscribe from publisher that we just created...
return [
Meteor.subscribe('queryBorrowerTypeDesktop')
];
},
data: function() {
if(Meteor.userId())
{
// also include the sorting and limit so your page will not crash. change accordingly.
return {
borrowerDetails: BorrowerDetails.find({},{sort: {name: -1}, limit: 30}),
}
}
}
});
Note that in data, BorrowerDetails.find() does not need to filter by anything because it has been filtered during the subscribe, which has been cached in MiniMongo in your browser.