Mongoose delete operation [duplicate] - node.js

Here is array structure
contact: {
phone: [
{
number: "+1786543589455",
place: "New Jersey",
createdAt: ""
}
{
number: "+1986543589455",
place: "Houston",
createdAt: ""
}
]
}
Here I only know the mongo id(_id) and phone number(+1786543589455) and I need to remove that whole corresponding array element from document. i.e zero indexed element in phone array is matched with phone number and need to remove the corresponding array element.
contact: {
phone: [
{
number: "+1986543589455",
place: "Houston",
createdAt: ""
}
]
}
I tried with following update method
collection.update(
{ _id: id, 'contact.phone': '+1786543589455' },
{ $unset: { 'contact.phone.$.number': '+1786543589455'} }
);
But it removes number: +1786543589455 from inner array object, not zero indexed element in phone array. Tried with pull also without a success.
How to remove the array element in mongodb?

Try the following query:
collection.update(
{ _id: id },
{ $pull: { 'contact.phone': { number: '+1786543589455' } } }
);
It will find document with the given _id and remove the phone +1786543589455 from its contact.phone array.
You can use $unset to unset the value in the array (set it to null), but not to remove it completely.

You can simply use $pull to remove a sub-document.
The $pull operator removes from an existing array all instances of a value or values that match a specified condition.
Collection.update({
_id: parentDocumentId
}, {
$pull: {
subDocument: {
_id: SubDocumentId
}
}
});
This will find your parent document against given ID and then will remove the element from subDocument which matched the given criteria.
Read more about pull here.

In Mongoose:
from the document:
To remove a document from a subdocument array we may pass an object
with a matching _id.
contact.phone.pull({ _id: itemId }) // remove
contact.phone.pull(itemId); // this also works
See Leonid Beschastny's answer for the correct answer.

To remove all array elements irrespective of any given id, use this:
collection.update(
{ },
{ $pull: { 'contact.phone': { number: '+1786543589455' } } }
);

To remove all matching array elements from a specific document:
collection.update(
{ _id: id },
{ $pull: { 'contact.phone': { number: '+1786543589455' } } }
);
To remove all matching array elements from all documents:
collection.updateMany(
{ },
{ $pull: { 'contact.phone': { number: '+1786543589455' } } }
);

Given the following document in the profiles collection:
{ _id: 1, votes: [ 3, 5, 6, 7, 7, 8 ] }
The following operation will remove all items from the votes array that are greater than or equal to ($gte) 6:
db.profiles.update( { _id: 1 }, { $pull: { votes: { $gte: 6 } } } )
After the update operation, the document only has values less than 6:
{ _id: 1, votes: [ 3, 5 ] }
If you multiple items the same value, you should use $pullAll instead of $pull.
In the question having a multiple contact numbers the same use this:
collection.update(
{ _id: id },
{ $pullAll: { 'contact.phone': { number: '+1786543589455' } } }
);
it will delete every item that matches that number. in contact phone
Try reading the manual.

Related

Remove duplicate key but keep object where other key is lowest with Mongoose

I have recently shifted to MongoDB and Mongoose with Node.js. And I am wrapping my head around it all coming from SQL.
I have a collection where documents have a similar structure to the following:
{
name: String
rank: Number
}
Sometimes the name might be the same, but the rank will always be different.
I would like to remove all duplicates of name, but retain the object that has the LOWEST rank.
For instance, if my collection looked like this:
{
name: "name1"
rank: 3
},
{
name: "name1"
rank: 4
},
{
name: "name1"
rank: 2
}
I would like to remove all objects where name is the same except for:
{
name: "name1"
rank: 2
}
Is this possible to do with mongoose?
Here is my approach:
const found = await db.collection.aggregate([
{
$group: {
_id: "$name",
minRank: {
$min: "$rank"
}
}
},
])
await db.collection.deleteMany({
$or: found.map(item => ({
name: item._id,
rank: { $ne: item.minRank }
}))
})
Explanation:
From my point of view your solution would result in many unnecessary calls being made, which would result in a terrible time of execution. My solution exactly contains two steps:
find for each document's property name the corresponding lowest rank available.
delete each document, where the name is equal to one of those names and the rank is not equal to the actual lowest rank found.
Additional notes:
If not already done, you should probably define an index on the name property of your schema for performance reasons.
Okay, I figured it out using aggregate:
const duplicates = await collectionName.aggregate([
{
$group: {
_id: "$name",
dups: { $addToSet: "$_id" },
count: { $sum: 1 }
}
},
{
$match: {
count: { $gt: 1 }
}
}
]);
duplicates.forEach(async (item) => {
const duplicate_names = item.dups;
const duplicate_name = await collectionName.find({ _id: { $in: duplicate_names } }).sort({ rank: 1 });
duplicate_name.shift();
duplicate_name.forEach(async (item) => {
await collectionName.deleteOne({ _id: item._id });
});
});

Can mongo has $cond in $push?

I need to push 1 item to array and save it to mongo if that item is not existed in array.
Sample: I have a record with an array
{
_id: ObjectId('xxxxx'),
userEmails: [
{
email: 'xxx#gmail.com,
addedAt: ISODate('xxx')
}
]
}
Current query:
db.users.updateOne(
{ _id: ObjectId('xxxxx') },
{
$push: {
userEmails: {
email: 'xxx#gmail.com',
addedAt: new Date(),
}
}
}
);
I expect if xxx#gmail.com is existed, it shouldn't pushed to array. I don't want array have duplicated items
Here We are specifying condition that if xxx#gmail.com is not inside userEmail then only we are pushing data.
db.users.updateOne(
{ _id: ObjectId('xxxxx'),"userEmails.email":{$ne: "xxx#gmail.com"} },
{
$push: {
userEmails: {
email: 'xxx#gmail.com',
addedAt: new Date(),
}
}
});
If you want to have a condition in $push, the best way to go will be to go with the $nin operation.
({name: {$nin: ["Shehroz", "virk"]}})
You can replace name with the user Email, so that it verifies the condition before updating

How can I update a document's nested array of object item by 1?

I'm trying to update a mongoose document with the help of findOneAndUpdate but I'm unable to do so. The document looks like this in the database:
{
'docId': 1001,
'totalViews': 3,
'docInfo': [
{
id: 1,
views: 2
},
{
id: 2,
views: 1
}
]
}
I'm trying to update totalViews by 1 which will make the total count to be 4. And I also need to update the second object's views property by 1 in imageInfo array. Which will have a views count of 2.
I tried doing this by first fetching the whole document with the help of:
const doc = await Doc.find({ docId: 1001 });
Then found the index of the docInfo array item which needs to be updated. Which is the object with id 2.
const docIndex = doc[0].docInfo.findIndex( item => {
return item.id === 2;
});
Then used findOneAndUpdate to update the items:
await Doc.findOneAndUpdate(
{ docId: 1001, "docInfo.id": 2 },
{
$set: {
[ `docInfo.${2}.views` ]: 1++,
'totalViews': 1++
}
}, { new: true }
);
With this I'm getting this error:
SyntaxError: Invalid left-hand side expression in postfix operation
What am I doing wrong here?
What you are doing is invalid, you can use $inc operator to increment a number, and don't need to find a query as well,
await Doc.findOneAndUpdate(
{ docId: 1001, "docInfo.id": 2 },
{
$inc: {
'docInfo.$.views': 1,
'totalViews': 1
}
},
{ new: true }
);
Playground

MongoDB assymetrical return of data, first item in array returned in full, the rest with certain properties omitted?

I'm new to MongoDB and getting to grips with its syntax and capabilities. To achieve the functionality described in the title I believe I can create a promise that will run 2 simultaneous queries on the document - one to get the full content of one item in the array (or at least the data that is omitted in the other query, to re-add after), searched for by most recent date, the other to return the array minus specific properties. I have the following document:
{
_id : ObjectId('5rtgwr6gsrtbsr6hsfbsr6bdrfyb'),
uuid : 'something',
mainArray : [
{
id : 1,
title: 'A',
date: 05/06/2020,
array: ['lots','off','stuff']
},
{
id : 2,
title: 'B',
date: 28/05/2020,
array: ['even','more','stuff']
},
{
id : 3,
title: 'C',
date: 27/05/2020,
array: ['mountains','of','knowledge']
}
]
}
and I would like to return
{
uuid : 'something',
mainArray : [
{
id : 1,
title: 'A',
date: 05/06/2020,
array: ['lots','off','stuff']
},
{
id : 2,
title: 'B'
},
{
id : 3,
title: 'C'
}
]
}
How valid and performant is the promise approach versus constructing one query that would achieve this? I have no idea how to perform such 'combined-rule'/conditions in MongoDB, if anyone could give an example?
If your subdocument array you want to omit is not very large. I would just remove it at the application side. Doing processing in MongoDB means you choose to use the compute resources of MongoDB instead of your application. Generally your application is easier and cheaper to scale, so implementation at the application layer is preferable.
But in this exact case it's not too complex to implement it in MongoDB:
db.collection.aggregate([
{
$addFields: { // keep the first element somewhere
first: { $arrayElemAt: [ "$mainArray", 0] }
}
},
{
$project: { // remove the subdocument field
"mainArray.array": false
}
},
{
$addFields: { // join the first element with the rest of the transformed array
mainArray: {
$concatArrays: [
[ // first element
"$first"
],
{ // select elements from the transformed array except the first
$slice: ["$mainArray", 1, { $size: "$mainArray" }]
}
]
}
}
},
{
$project: { // remove the temporary first elemnt
"first": false
}
}
])
MongoDB Playground

Mongoose, update values in array of objects

Is there a way to update values in an object?
{
_id: 1,
name: 'John Smith',
items: [{
id: 1,
name: 'item 1',
value: 'one'
},{
id: 2,
name: 'item 2',
value: 'two'
}]
}
Lets say I want to update the name and value items for item where id = 2;
I have tried the following w/ mongoose:
var update = {name: 'updated item2', value: 'two updated'};
Person.update({'items.id': 2}, {'$set': {'items.$': update}}, function(err) { ...
Problem with this approach is that it updates/sets the entire object, therefore in this case I lose the id field.
Is there a better way in mongoose to set certain values in an array but leave other values alone?
I have also queried for just the Person:
Person.find({...}, function(err, person) {
person.items ..... // I might be able to search through all the items here and find item with id 2 then update the values I want and call person.save().
});
You're close; you should use dot notation in your use of the $ update operator to do that:
Person.update({'items.id': 2}, {'$set': {
'items.$.name': 'updated item2',
'items.$.value': 'two updated'
}}, function(err) { ...
model.update(
{ _id: 1, "items.id": "2" },
{
$set: {
"items.$.name": "yourValue",
"items.$.value": "yourvalue",
}
}
)
MongoDB Document
There is a mongoose way for doing it.
const itemId = 2;
const query = {
item._id: itemId
};
Person.findOne(query).then(doc => {
item = doc.items.id(itemId );
item["name"] = "new name";
item["value"] = "new value";
doc.save();
//sent respnse to client
}).catch(err => {
console.log('Oh! Dark')
});
There is one thing to remember, when you are searching the object in array on the basis of more than one condition then use $elemMatch
Person.update(
{
_id: 5,
grades: { $elemMatch: { grade: { $lte: 90 }, mean: { $gt: 80 } } }
},
{ $set: { "grades.$.std" : 6 } }
)
here is the docs
For each document, the update operator $set can set multiple values, so rather than replacing the entire object in the items array, you can set the name and value fields of the object individually.
{'$set': {'items.$.name': update.name , 'items.$.value': update.value}}
Below is an example of how to update the value in the array of objects more dynamically.
Person.findOneAndUpdate({_id: id},
{
"$set": {[`items.$[outer].${propertyName}`]: value}
},
{
"arrayFilters": [{ "outer.id": itemId }]
},
function(err, response) {
...
})
Note that by doing it that way, you would be able to update even deeper levels of the nested array by adding additional arrayFilters and positional operator like so:
"$set": {[`items.$[outer].innerItems.$[inner].${propertyName}`]: value}
"arrayFilters":[{ "outer.id": itemId },{ "inner.id": innerItemId }]
More usage can be found in the official docs.
cleaner solution using findOneAndUpdate
await Person.findOneAndUpdate(
{ _id: id, 'items.id': 2 },
{
$set: {
'items.$.name': 'updated item2',
'items.$.value': 'two updated',
}
},
);
In Mongoose, we can update array value using $set inside dot(.) notation to specific value in following way
db.collection.update({"_id": args._id, "viewData._id": widgetId}, {$set: {"viewData.$.widgetData": widgetDoc.widgetData}})
Having tried other solutions which worked fine, but the pitfall of their answers is that only fields already existing would update adding upsert to it would do nothing, so I came up with this.
Person.update({'items.id': 2}, {$set: {
'items': { "item1", "item2", "item3", "item4" } }, {upsert:
true })
I had similar issues. Here is the cleanest way to do it.
const personQuery = {
_id: 1
}
const itemID = 2;
Person.findOne(personQuery).then(item => {
const audioIndex = item.items.map(item => item.id).indexOf(itemID);
item.items[audioIndex].name = 'Name value';
item.save();
});
Found this solution using dot-object and it helped me.
import dot from "dot-object";
const user = await User.findByIdAndUpdate(id, { ...dot.dot(req.body) });
I needed to update an array element with dynamic key-value pairs.
By mapping the update object to new keys containing the $ update operator, I am no longer bound to know the updated keys of the array element and instead assemble a new update object on the fly.
update = {
name: "Andy",
newKey: "new value"
}
new_update = Object.fromEntries(
Object.entries(update).map(
([k, v], i) => ["my_array.$." + k, v]
)
)
console.log({
"$set": new_update
})
In mongoose we can update, like simple array
user.updateInfoByIndex(0,"test")
User.methods.updateInfoByIndex = function(index, info) ={
this.arrayField[index]=info
this.save()
}
update(
{_id: 1, 'items.id': 2},
{'$set': {'items.$[]': update}},
{new: true})
Here is the doc about $[]: https://docs.mongodb.com/manual/reference/operator/update/positional-all/#up.S[]

Resources