how to get the specific message by _id.
I have a database schema as shown below:
{
"_id": ObjectID("5846eedaf0b51ed02ed846e2"),
"name": "conversation name"
"messages": [
{
"_id": ObjectID("584820a96866b6283361a4b9"),
"content": "hello",
"status": 0,
"type": 0
},
{
"_id": ObjectID("584820d56866b6283361a4ba"),
"content": "voices/1481122005696.mp3",
"status": 0,
"type": 3
}
]
}
db.collection.find({}, {
'messages': {
$elemMatch: {
'_id': ObjectId("584820a96866b6283361a4b9")
}
}
})
This will match on all documents in your collection, and return the matching array subfield in the projection. See the link posted in Yogesh's comment.
Since you tagged mongoose, I put it like this, but the query syntax is valid because is part of mongoDB query syntax:
Conversation.findOne({
"messages._id": "584820a96866b6283361a4b9"
}, function(err, document){
if (err) {
console.log(err)
return
}
var message = document.messages.id("584820a96866b6283361a4b9")
})
The finOne() method will return the full parent document with all the messages (subdocuments) and other properties. You then need to filter out the subdocument. Mongoose provides a way to do this easily with: document.messages.id("584820a96866b6283361a4b9") where document would be the data object passed to the find callback
See:
Match a Field Without Specifying Array Index on
https://docs.mongodb.com/v3.2/tutorial/query-documents/#query-on-arrays
Related
Lets say I have a mongoose schema, something like:
mongoose.Schema({
website_id:mongoose.SchemaTypes.ObjectId,
data:Object
})
where data field contains JSON Object. Something like:
{
"actions":[
{
"action":"pageChange",
"url":"http://localhost:3000/login",
"dom":"",
"timestamp":1653341614846
},
{
"action":"pageChange",
"url":"http://localhost:3000/signup",
"dom":"",
"timestamp":1653341626442
},
{
"action":"pageChange",
"url":"http://localhost:3000/view",
"dom":"",
"timestamp":1653341626442
},
{
"action":"pageChange",
"url":"http://localhost:3000/login",
"dom":"",
"timestamp":1653341626442
}
]
}
Is there any way I can get all documents, where data field object contains http://localhost:3000/login as url, without getting all the documents first and looping them through.
Object is going to be dynamic generated, and items will repeat themselves
Of course, there are several ways and in this case, one of the best ways is to use "aggregate"
db.collection.aggregate([
{$unwind: "$actions"},
{ $match: {"actions.url": "http://localhost:3000/login"}},
{$group: {
_id: "$_id",
actions: {$push: "$actions"}
}
}
])
return Response :
{
"actions": [
{
"action": "pageChange",
"dom": "",
"timestamp": 1.653341614846e+12,
"url": "http://localhost:3000/login"
},
{
"action": "pageChange",
"dom": "",
"timestamp": 1.653341626442e+12,
"url": "http://localhost:3000/login"
}
]
}
If i find other or better methods, I'll definitely share..
I hope this solution helps you.
Sure you can do that. You can specify the object nesting in form of string in the query.
await MyModel.find({ 'data.objectKey.items.item': 'text I want to find' }).exec();
I have collection with name products with almost 100k documents. I want to introduce a new key called secondaryKey with unique value uuid in all the documents.
I do this using nodejs.
Problem I am facing:-
When I try the below query,
db.collection('products').updateMany({},{"$set":{secondaryKey: uuid()}});
Here it updates all the documents with same uuid value,
I try with loop to update document one by one,but here issues is I don't have filter value in updateOne because I want to update all the documents.
Can anyone please help me here.
Thanks :)
If you are using MongoDB version >= 4.4 You can try this:
db.products.updateMany(
{},
[
{
$set: {
secondaryKey: {
$function: {
body: function() {
return UUID().toString().split('"')[1];
},
args: [],
lang: "js"
}
}
}
}
]
);
Output
[
{
"_id": ObjectId("..."),
"secondaryKey": "f41b15b7-a0c5-43ed-9d15-69dbafc0ed29"
},
{
"_id": ObjectId("..."),
"secondaryKey": "50ae7248-a92e-4b10-be7d-126b8083ff64"
},
{
"_id": ObjectId("..."),
"secondaryKey": "fa778a1a-371b-422a-b73f-8bcff865ad8e"
}
]
Since it's not the same value you want to put in each document you have to use the loop.
In your loop, you have to update the current document of the iteration. So you have to filter with the _id in the updateOne
The above reply didn't work for me. Plus, it compromises security when you enable javascript on your database (see here $function and javascript enabling on database). The best way is to not overload your server, do your work on local as below:
const { nanoid, customAlphabet } = require('nanoid')
async function asdf() {
const movies = await client.db("localhost").collection("productpost");
var result2 = []
let result = await movies.find({}).toArray()
result.forEach(element => {
const nanoid = customAlphabet('1234567890', 10)
console.log(element.price)
element.price = 4
element.id = nanoid()
result2.push(element)
});
console.log("out reult2", result2)
await movies.deleteMany({})
await movies.insertMany(result2)
})
It will delete any objects on your collections and update with the new ones. Using nanoid as uniqueids.
This is the database object array after adding unique id:
{ "_id": { "$oid": "334a98519a20b05c20574dd1" }, "attach": "[\"http://localhost:8000/be/images/2022/4/bitfinicon.png\"]", "title": "jkn jnjn", "description": "jnjn", "price": 4, "color": "After viewing I am 48.73025772956596% more satisfied with life.", "trademark": "", "category": "[]", "productstate": "Published", "createdat": { "$date": "2022-04-03T17:40:54.743Z" }, "language": "en"}
P.S: Please backup your collection before doing this or filter the array on your needs for not going through all collection.
I'd like to do a bulk query to cloudant db.
By supplying a list of _ids (primary key), and have db return any documents with matching _ids.
This is working as shown below. But I'd like to return _id, _rev and field_name also. Is there a way to do this without using include_docs=true?
Request:
http://{db-host}/{db-name}/_all_docs?keys=["1e0a2d30d18d95b9bcc05d92c8736eab","181687d2f16debc10f9e365cc4002371"]
Response:
{
"total_rows": 3,
"rows": [{
"id": "1e0a2d30d18d95b9bcc05d92c8736eab",
"key": "1e0a2d30d18d95b9bcc05d92c8736eab",
"value": {
"rev": "1-a26b67f478e4f3f8fd49779a66fc7949"
}
}, {
"id": "181687d2f16debc10f9e365cc4002371",
"key": "181687d2f16debc10f9e365cc4002371",
"value": {
"rev": "1-7338901ca1c5c06ef81a6971aa6e8f9d"
}
}]
}
No. The index of _all_docs does not contain the field_name data.
The only way to get it using this view is with include_docs.
Otherwise you will have to write (and index) your own view that emits what you want.
map: function(doc) {
emit(doc._id, { _id: doc._id, _rev: doc._rev, field_name: doc.field_name });
}
An alternative to using include_docs or manually populating all fields is to emit docs as values in a view, like that:
emit(doc._id, doc);
I have a Model called Post, witch contains an property array with user-ids for users that have liked this post.
Now, i need to query the post model, and mark the returned results with likedBySelf true/false for use in by client - is this possible?
I dont have to store the likedBySelf property in the database, just modify the results to have that property.
A temporary solution i found was to do 2 queries, one that finds the posts that is liked by user x, and the ones that have not been liked by user x, and en map (setting likedBySelf true/false) and combine the 2 arrays and return the combined array. But this gives some limitations to other query functions such as limit and skip.
So now my queries looks like this:
var notLikedByQuery = Post.find({likedBy: {$ne: req.body.user._id}})
var likedByQuery = Post.find({likedBy: req.body.user._id})
(I'm using the Mongoose lib)
PS. A typical post can look like this (JSON):
{
"_id": {
"$oid": "55fc463c83b2d2501f563544"
},
"__t": "Post",
"groupId": {
"$oid": "55fc463c83b2d2501f563545"
},
"inactiveAfter": {
"$date": "2015-09-25T17:13:32.426Z"
},
"imageUrl": "https://hootappprodstorage.blob.core.windows.net/devphotos/55fc463b83b2d2501f563543.jpeg",
"createdBy": {
"$oid": "55c49e2d40b3b5b80cbe9a03"
},
"inactive": false,
"recentComments": [],
"likes": 8,
"likedBy": [
{
"$oid": "558b2ce70553f7e807f636c7"
},
{
"$oid": "559e8573ed7c830c0a677c36"
},
{
"$oid": "559e85bced7c830c0a677c43"
},
{
"$oid": "559e854bed7c830c0a677c32"
},
{
"$oid": "559e85abed7c830c0a677c40"
},
{
"$oid": "55911104be2f86e81d0fb573"
},
{
"$oid": "559e858fed7c830c0a677c3b"
},
{
"$oid": "559e8586ed7c830c0a677c3a"
}
],
"location": {
"type": "Point",
"coordinates": [
10.01941398718396,
60.96738099591897
]
},
"updatedAt": {
"$date": "2015-09-22T08:45:41.480Z"
},
"createdAt": {
"$date": "2015-09-18T17:13:32.426Z"
},
"__v": 8
}
#tskippe you can use a method like following to process whether the post is liked by the user himself and call the function anywhere you want.
var processIsLiked = function(postId, userId, doc, next){
var q = Post.find({post_id: postId});
q.lean().exec(function(err,res){
if(err) return utils.handleErr(err, res);
else {
if(_.find(doc.post.likedBy,userId)){ //if LikedBy array contains the user
doc.post.isLiked = true;
} else {
doc.post.isLiked = false;
}
});
next(doc);
}
});
}
Because you are using q.lean() you dont need to actually persist the data. You need to just process it , add isLiked field in the post and send back the response. **note that we are manuplating doc directly. Also you chan tweek it to accept doc containing array of posts and iterating it and attach an isLiked field to each post.
I found that MongoDB's aggregation with $project tequnique was my best bet. So i wrote up an aggregation like this.
Explanation:
Since i want to keep the entire document, but $project purpose is to modify the docs, thus you have to specify the properties you want to keep. A simple way of keeping all the properties is to use "$$ROOT".
So i define a $project, set all my original properties to doc: "$$ROOT", then create a new property "likedBySelf", which is marked true / false if a specified USERID is in the $likedBy set.
I think that this is more clean and simple, than querying every single model after a query to set a likedBySelf flag. It may not be faster, but its cleaner.
Model.aggregate([
{ $project: {
doc: "$$ROOT",
likedBySelf: {
$cond: {
"if": { "$setIsSubset": [
[USERID],
"$likedBy"
]},
"then": true,
"else": false
}
}
}}
]);
I have the following schema. I am using node.js with mongodb
attributes: {
type: { type: 'string' },
title: { type:'string' },
description: { type:'string' },
is_active: { type:'boolean',defaultsTo:true },
createdBy: { type:'json' },
attachments:{ type:'array' }
}
arr = [{
'id':attResult.id,
'subtype':type,
'title' : attResult.title,
'body' : attResult.body,
'filetype' : attResult.filetype
}];
I am trying to push a attachments into the 'attachments' array that will be unique to the document.
This is the my query.
books.update(
{ id: refid },
{ $push: { attachments: arr } }
).done(function (err, updElem) {
console.log("updElem" + JSON.stringify(updElem));
});
What is the problem in my query,no error but not updated attachments.
I want my result to be this:
{
"_id" : 5,
"attachments": [
{
"id": "xxxxxxx",
"subtype": "book",
"title": "xxxx",
"body": "xxxx" ,
"filetype" : "xxxxx"
},
{
"id": "xxxxxxx",
"subtype": "book",
"title": "xxxx",
"body": "xxxx",
"filetype": "xxxxx"
}
]
}
Someone who trying to push the element into an array is possible now, using the native mongodb library.
Considering the following mongodb collection object
{
"_id" : 5,
"attachments": [
{
"id": "xxxxxxx",
"subtype": "book",
"title": "xxxx",
"body": "xxxx" ,
"filetype" : "xxxxx"
},
{
"id": "xxxxxxx",
"subtype": "book",
"title": "xxxx",
"body": "xxxx",
"filetype": "xxxxx"
}
]
}
arr = [{
'id':'123456',
'subtype':'book',
'title' : 'c programing',
'body' :' complete tutorial for c',
'filetype' : '.pdf'
},
{
'id':'123457',
'subtype':'book',
'title' : 'Java programing',
'body' :' complete tutorial for Java',
'filetype' : '.pdf'
}
];
The following query can be used to push the array element to "attachments" at the end. $push or $addToSet can be used for this.
This will be inserting one object or element into attachments
db.collection('books').updateOne(
{ "_id": refid }, // query matching , refId should be "ObjectId" type
{ $push: { "attachments": arr[0] } } //single object will be pushed to attachemnts
).done(function (err, updElem) {
console.log("updElem" + JSON.stringify(updElem));
});
This will be inserting each object in the array into attachments
db.collection('books').updateOne(
{ "_id": refid }, // query matching , refId should be "ObjectId" type
{ $push: { "attachments":{$each: arr} } } // arr will be array of objects
).done(function (err, updElem) {
console.log("updElem" + JSON.stringify(updElem));
});
Looking at your question a little bit more I'm betting that you are actually using "sails" here even though your question is not tagged as such.
The issue here is that the waterline ODM/ORM has it's own ideas about what sort of operations are actually supported since it tries to be agnostic between working with SQL/NoSQL backends and sort of demands a certain may of doing things.
The result is that updates with $push are not really supported at present and you need more of a JavaScript manipulation affair. So in fact you need to manipulate this via a .findOne and .save() operation:
books.findOne(refid).exec(function(err,book) {
book.attachments.push( arr[0] );
book.save(function(err){
// something here
});
});
Part of that is "waterline" shorthand for what would otherwise be considered an interchangeable use of _id and id as terms, where just specifying the id value as a single argument implies that you are referring to the id value in your query selection.
So unless you replace the waterline ODM/ORM you are pretty much stuck with this AFAIK until there is a decision to maintain this logic in a way that is more consistent with the MongoDB API or otherwise allow access to the "raw" driver interface to perform these .update() operations.
For reference though, and has been alluded to, your general "shell" syntax or what would otherwise be supported in MongoDB specific drivers is like this with the deprecation of the $pushAll operator and the intention being to merge the functionality with the $push and $addToSet operators using the $each modifier:
db.collection.update(
{ "_id": ObjectId(refid) }, // should be important to "cast"
{
"$push": {
"attachments": {
"$each": arr
}
}
}
)
So that syntax would work where it applies, but for you I am thinking that in "sails" it will not.
That gives you some food for thought, and some insight into the correct way to do things.
You are trying to insert an array as an element into your array. You may want to look at $pushAll as a short term solution. This operator is deprecated however see here.
Alternatively you can simply iterate over your array, and each iteration push an element from your array into attachments (this is the recommended approach by Mongo devs).