i am a beginner in mongoose and i am trying to delete an element in array but i am facing troubles to do it
my schema is like this
name : {
type: String,
trim : true
},
pictures: {
type : Array,
required : false
},
and in my database it looks like this
{
"_id" : ObjectId("5eb67e7c74b35b205362b7f4"),
"title" : "john doe",
"pictures" : [
"img1.jpg",
"img2.png",
"img3.jpg",
"img4.jpg",
"img5.jpg"
]
}
how can i delete an item in the array of pictures?
You need $pull operator:
await Model.updateOne({"_id" : ObjectId("5eb67e7c74b35b205362b7f4")}, {$pull: { "pictures": "img1.jpg"}});
This is my document.
{
"group_name" : "Test Group 6 (Edit)",
"created_on" : "1464367826787",
"group_id" : "group_14",
"members" : [
{
"user_id" : "user_7",
"added_on" : "1464367826787"
}
],
"is_deleted" : 0
}
I'm having list of user_ids and I need to remove user_ids which are not in the list of user_ids I have. How to remove "user_50" if input list = ["user_7"] ?
You need to use the $nin operator to select your documents, the updateMany method if you want to update multiple documents or updateOne method to update a single document.
db.users.updateMany(
{},
{ "$pull": { "members": { "user_id": { "$nin": [ "user_7" ] } } }}
)
db.users.update(
{},
{$pull:
{members:{'user_id':{$ne:"user_7"}}}}, {multi:true})
I have a document structure like
{
"_id" : ObjectId("52263922f5ebf05115bf550e"),
"Fields" : [
{
"Field" : "Lot No",
"Rules" : [ ]
},
{
"Field" : "RMA No",
"Rules" : [ ]
}
]
}
I have tried to update by using the following code to push into the Rules Array which will hold objects.
db.test.update({
"Fields.Field":{$in:["Lot No"]}
}, {
$addToSet: {
"Fields.Field.$.Rules": {
"item_name": "my_item_two",
"price": 1
}
}
}, false, true);
But I get the following error:
can't append to array using string field name [Field]
How do I do the update?
You gone too deep with that wildcard $. You match for an item in the Fields array, so you get a access on that, with: Fields.$. This expression returns the first match in your Fields array, so you reach its fields by Fields.$.Field or Fields.$.Result.
Now, lets update the update:
db.test.update({
"Fields.Field": "Lot No"
}, {
$addToSet: {
"Fields.$.Rules": {
'item_name': "my_item_two",
'price':1
}
}
}, false, true);
Please note that I've shortened the query as it is equal to your expression.
How do you update the sku value within an array as in example "B". Should I go with A over B?
Option A - Object
Scheme
"data" : {
"products" : {
235099432:{
"product_id" : 101242538,
"sku" : "",
"variant_id" : 235099432
},
]
}
Update
db.col.update({
"data.products.235099432.variant_id": 235099432
}, {
$set: {
"data.products.235099432.sku": "ITM-RED-212"
}
});
Option B - Array
Scheme
"data" : {
"products" : [
{
"product_id" : 101242538,
"sku" : "",
"variant_id" : 235099432
},
]
}
You can use the $ position operator to identify the products array element to update that matches your filter:
db.col.update({
"data.products.variant_id": 235099432
}, {
$set: {
"data.products.$.sku": "ITM-RED-212"
}
});
My vote would be option B; the use of dynamic keys in option A can get very messy.
I'm trying to update a single subelement contained within an array in a mongodb document. I want to reference the field using its array index (elements within the array don't have any fields that I can guarantee will be unique identifiers). Seems like this should be easy to do, but I can't figure out the syntax.
Here's what I want to do in pseudo-json.
Before:
{
_id : ...,
other_stuff ... ,
my_array : [
{ ... old content A ... },
{ ... old content B ... },
{ ... old content C ... }
]
}
After:
{
_id : ...,
other_stuff ... ,
my_array : [
{ ... old content A ... },
{ ... NEW content B ... },
{ ... old content C ... }
]
}
Seems like the query should be something like this:
//pseudocode
db.my_collection.update(
{_id: ObjectId(document_id), my_array.1 : 1 },
{my_array.$.content: NEW content B }
)
But this doesn't work. I've spent way too long searching the mongodb docs, and trying different variations on this syntax (e.g. using $slice, etc.). I can't find any clear explanation of how to accomplish this kind of update in MongoDB.
As expected, the query is easy once you know how. Here's the syntax, in python:
db["my_collection"].update(
{ "_id": ObjectId(document_id) },
{ "$set": { 'documents.'+str(doc_index)+'.content' : new_content_B}}
)
Update of an array element referenced by an index (e.g. 1 ) in Mongo Shell can also be done by directly indicating the index value:
db.my_collection.update(
{_id : "document_id"},
{$set : {"my_array.1.content" : "New content B"}}
)
In mongo style, using '$' positional operator.
Check out this link for details.
db.my_collection.update(
{_id: ObjectId(document_id), my_array.1 : 1 },
{ $set: { "my_array.$.content" : "NEW content B" } }
)
When it's required to update an array element without knowing it's actual index but having a unique identifier of the element:
// Modify a comment in a bucket
db.POST_COMMENT.update(
{
"_id": ObjectId("5ec424a1ed1af85a50855964"),
"bucket.commentId": "5eaf258bb80a1f03cd97a3ad_lepf4f"
},
{
$set: {
"bucket.$.text": "Comment text changed",
"bucket.$.createdDate": ISODate("2015-12-11T14:12:00.000+0000")
}
}
)
Here "bucket.commentId" is the unique identifier of an array element.
A neat way to do it in Javascript, with backticks, is:
const index = 1;
... { $set: { [`myArray.${index}.value`]: "new content"} }, ...
db.my_collection.update(
{_id: ObjectId(document_id), my_array : { ... old content A ... } },
{ $set: { "my_array.$.content" : "NEW content B" } }
)
When it's required to update an array element without knowing it's an actual index but having a unique identifier of the element
db.getCollection('profiles').update(
{
'userId':'4360a380-1540-45d9-b902-200f2d346263',
'skills.name':'css'
},
{
$set: {'skills.$.proficiencyLevel': 5}
},
{
multi: true
}
)
If you want to update the authorName of the testimonial having _id = 60c4918d74c30165ba585c14 from the following document:
"business": {
"ownerId": "60a5ebad7432d91b853c0277",
"testimonials": [
{
"_id": "60c4912877dd5664f2201b08",
"authorName": "user1",
"authorBio": "User from 10 years",
"image": "user1/img1",
"review": "asdfiuahsdfpoiuashdpfoaspdlfkjn;alsfpuoh"
},
{
"_id": "60c4918d74c30165ba585c14",
"authorName": "user2",
"authorBio": "User from 3 years",
"image": "user/img1",
"review": "asdpfuahsfljnsadfoihsf."
}
],
"createdAt": "2021-06-11T20:12:56.666Z",
"updatedAt": "2021-06-12T11:11:56.696Z",
}
Then the following mongoose query works:
await BusinessModel.updateOne(
{
'_id': Mongoose.Types.ObjectId(businessId),
'testimonials._id': Mongoose.Types.ObjectId('60c4918d74c30165ba585c14')
},
{
$set: { 'testimonials.$.authorName' : 'new author name' }
}
);
Also refer to https://docs.mongodb.com/drivers/node/fundamentals/crud/write-operations/embedded-arrays/
You can use the updateOne function of mongoDB passing the index of the element in array, if the key of old content B is "value" per example:
[
...
"value" : "old content A"
"value" : "old content B"
"value" : "old content C"
...
]
the command should be like this:
db.collection.updateOne({"_id" : "...,"},{$set: {"my_array.1.value": "NEW content B"}})
If you have a "plain" array containing simple strings, this did the trick:
db.paintings.insertMany([
{_id: 1, colors: ["red", "blue", "green"]},
{_id: 2, colors: ["red", "yellow"]}
db.paintings.updateMany(
{colors: "red"},
{$set: {"colors.$": "magenta"}})
the positional $ operator acts as a placeholder for the first element that matches the query document
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