Mongoose aggregate lookup. Upvoting indicates when questions and answers are useful.

Mongoose aggregate lookup aggregate() method uses the collation for the top-level collection/view on which the db. match({ _id: new mongoose. allowDiskUse]» if true, the MongoDB server will use the hard drive to store data during this aggregation object « [options. Aggregation $lookup pipeline, querying an array of embedded documents by an array of possible values. This is likely that user_id in the assignments collection is actually a string. 1. collation] «Object» object see Aggregate Jun 12, 2024 · populate (Mongoose ORM): populate is a feature provided by the Mongoose ODM (Object Data Modeling) for MongoDB. Hence, I want the result to be an object instead an array with one item. I've tried various way with this and still can't find the correct way to filter my results. Schema({ _id: mongoose. What's reputation and how do I get it? Instead, you can save this post to reference later. Jan 12, 2020 · You'll need to complete a few actions and gain 15 reputation points before being able to upvote. Dec 30, 2023 · In conclusion, using Mongoose aggregation functions such as min, max, average, sum, and count is quintessential for database data processing and analysis. log(). deleteMany() Model. js. In this article, we will expalin the aggregate() method, explain its syntax, usage, and provide code examples that demonstrate how to utilize this method to perform complex Jul 23, 2025 · This article will dive deep into the Mongoose Aggregate API, explaining its usage, syntax, and practical examples for beginners and experienced developers alike. Jun 15, 2017 · Show the actual data as viewed from the mongo shell rather than a console. Each of these functions returns a mongoose Query object. Is there a different approach I should take if I want a more performant query? e. I've done some research and tried to apply what I've found but something just seems to escape me. Schema({ name: 'string', restId: 'string', saved: {type: 'date', default: Date. May 3, 2025 · When working with MongoDB and Mongoose, you might often find yourself needing more than just basic queries. Population is the process of automatically replacing the specified paths in the document with document (s) from other collection (s). I try to get user data with the related user group data and with the (user group) related access data: Example data: users collection: _id: ObjectId('641c689e0974d4617351897f'), name: 'Bob', email: 'bob@email. maxTimeMS] «Number» number limits the time this aggregation will run, see MongoDB docs on maxTimeMS [options. allowDiskUse] «Boolean» boolean if true, the MongoDB server will use the hard drive to store data during this aggregation [options. for that, I have used lookup aggression. aggregate(pipeline). Aug 23, 2020 · Is it possible to do a $lookup aggregation between two databases in Mongodb ? I try this documentation, but the results is empty array Sep 12, 2017 · I have this function in my moongose+mongodb: Blog. After your aggregation, do this: Aggregate. data, but here i need to get data matching in $lookup where userdetails. Instead of going {{myresult[0]. You want to enrich order documents with the corresponding product information: May 18, 2020 · Mongoose's aggregate() function is how you use MongoDB's aggregation framework with Mongoose. Player. 6 and above $lookup syntax it is quite simple to join nested fields without using $unwind. Nov 24, 2022 · -2 I think you have only one Database having Post and User collections and not two separate databases. maxTimeMS]» limits the time this aggregation will run, see MongoDB docs on maxTimeMS boolean « [options. This is where the MongoDB Aggregation Pipeline comes in. if you will, then follow my explanation to adapt it to new situations or try searching the internet again with your now increased Mongoose aggregate Lookup - How to filter by specific idI am trying to make a aggregate pipeline - $lookup to Nov 14, 2024 · Learn MongoDB Lookup Aggregations with syntax, examples, and practical tips. Aug 30, 2016 · It is not possible to query using lookup in two different db's. e I have the following schema: Aug 1, 2022 · How to get the first element from a child lookup in aggregation - Mongoose Asked 3 years, 3 months ago Modified 3 years, 2 months ago Viewed 2k times Aug 1, 2022 · How to get the first element from a child lookup in aggregation - Mongoose Asked 3 years, 3 months ago Modified 3 years, 2 months ago Viewed 2k times Dec 1, 2017 · Continue to help good content that is interesting, well-researched, and useful, rise to the top! To gain full voting privileges, May 1, 2023 · I am working on a fairly big sveltekit project and use MongoDB for NodeJs. Show your schema for each as well. With Mongoose, you can create sophisticated data pipelines to filter, group, and calculate data directly within MongoDB, enabling advanced analytics and reporting without additional computation in your application. Jan 25, 2021 · Another requirement was to have a possibility to choose a specific page on-demand, so the approach to use “ previous-next ”-like pagination, that based on cursors was prohibited immediately — its mongoose-paginate-v2 and *mongoose-aggregate-paginate-v2 *libraries. You can check the collection name by going to mongosh shell and To show list of all database show dbs To Feb 25, 2024 · here are my Schemas : const property = mongoose. Jan 29, 2019 · Mongoose aggregate with lookup and object array Asked 6 years, 1 month ago Modified 6 years, 1 month ago Viewed 184 times Mar 7, 2024 · Master the MongoDB aggregation pipeline. deleteOne() Model. findOne() Model. I have two Feb 18, 2021 · I am fetching list of records having some nested reference to other collection, I want to populate that nested ObjectId which is inside array of objects, with mongoDb aggregate lookup query. Jul 19, 2023 · In Mongoose, there's a great and useful feature called Population, which makes it possible to Tagged with mongodb, mongoose, lookup, aggregation. Oct 3, 2020 · I'm new to the aggregate feature with mongodb and mongoose and have been having difficulty getting the desired results after passing data through my pipeline. Working with Data aggregation Vinicius_Carvalho (Vinicius Carvalho) November 29, 2022, 10:16pm 1 Feb 2, 2021 · How to aggregate nested lookup array in mongoose? Asked 4 years, 2 months ago Modified 4 years, 2 months ago Viewed 252 times Jan 23, 2023 · return await database. With Angular, this makes a huge difference. but returned director casts content. startSession() starts a session on the default mongoose connection. data. $lookup in mongodb supports Performs a left outer join to an unsharded collection in the same database. May 16, 2025 · The Mongoose lookup() method is an incredibly powerful tool for performing left joins between collections in MongoDB. aggregate([{ "$match": {"user_id": userblog}}, { "$lookup": { from: "commen Nov 5, 2016 · The following is my code in App. Learn how to convert a value to an ObjectId. Is it possible to join?. You have used from:"Product" instead you need to use the word products because you need to provide the exact name of the collection that is formed in the database. I've setup an index and it works fine with Feb 22, 2023 · How to join another table in $lookup mongoose. Jul 18, 2023 · Mongoose aggregation is a powerful feature provided by the Mongoose library for MongoDB in Node. collation] «Object» object see Aggregate Feb 2, 2024 · This tutorial demonstrates how we can join multiple conditions using the lookup operator in MongoDB. I have a serverless Atlas project. Dec 13, 2022 · We currently have an aggregate query, that pulls all user records and then does a lookup in the office locations table. The populate () work fine but we need to use aggregate. js, provides an easy-to-use API for interacting with MongoDB databases. Remember, the more complex your queries, the more thought you should put into the performance implications. Takes 7 minutes on a collection with 9 million documents. Here is one document from the output after $lookup has been done to Nov 26, 2019 · This MongoDB $lookup tutorial is the first of a three-part aggregation query example that uses the $lookup, $project & $out stages. aggregate() . Dec 30, 2023 · The ability to filter documents by multiple fields in Mongoose is essential for building sophisticated data-driven applications. Mongoose's aggregate() is a thin wrapper, so any aggregation query that works in the MongoDB shell should work in Mongoose without any changes. May 10, 2022 · I have tried: db. Jul 23, 2025 · The aggregate() method in Mongoose is one of the most powerful features of MongoDB, enabling us to perform advanced data manipulations and transformations directly within your database. model ('Discipline'). Aug 24, 2021 · mongoose aggregate lookup in project Asked 4 years, 2 months ago Modified 4 years, 2 months ago Viewed 258 times Nov 17, 2022 · NestJS mongoose aggregate $lookup . Run an Aggregation Pipeline To run an aggregation pipeline, use: db. Can somebody tell me what is the problem? Mar 16, 2016 · 98 With the mongodb 3. Jul 31, 2021 · Hello : ) If i understant what you want right,you dont need lookup, you just need to filter the document, using that ids array as creteria. Problem with the aggregation here: menu return only menuItems and logo , and the … Mar 11, 2019 · So, these are my models let restaurantSchema = mongoose. Types. Apr 7, 2016 · If you question why would you $unwind as opposed to using $filter on the array, then read Aggregate $lookup Total size of documents in matching pipeline exceeds maximum document size for all the detail on why this is generally necessary and far more optimal. i. May 17, 2017 · updated my question with an example to clarify the issue The problem is surely with the names of collections. tournamentID", "foreignField":"TournamentID", "as":"Tennis-player"}}, { "$group": { "_id": { Name:"$Name" }, "total_qty": { "$sum": "$Tennis-player. The product document looks something like this: { "productPrice": [ { "rentalContractId": Learn about the $match aggregation stage, which filters documents to pass only those that match specified conditions to the next pipeline stage. I am using mongoose for communication with mongodb. Jul 12, 2018 · In which way is it wrong? What is it supposed to look like? Jan 30, 2018 · I have a collection called article_category which store all article_id belongs to the category with category_id with data format like so. findOneAndReplace() Model. Mar 6, 2017 · I'm working with the followings mongoose schemas: Question schema: var Question = new Schema({ title: String, content: String, createdBy: { type: Schema. Basic Usage To start with $lookup, imagine you have two collections: orders and products. Feb 10, 2017 · I have two schemas, one is User the other is Pet. May 14, 2023 · I'm trying to lookup every rentalContractId from rentalcontractdetails table. lookup({ from: 'User', foreignField: '_id', local Feb 14, 2024 · I am to fetching data from reviewRatings and used $lookup to get userdetails. to_list(int(limit)) I used the same code above to fetch model or merchant_name and it worked as expected in Python. name}}, I can simply Aggregate. In this guide, we’ll dive into creating aggregation pipelines with Mongoose Sep 28, 2021 · MongoDB aggregate $lookup not working with $group Asked 3 years, 9 months ago Modified 3 years, 9 months ago Viewed 495 times Sep 28, 2021 · MongoDB aggregate $lookup not working with $group Asked 3 years, 9 months ago Modified 3 years, 9 months ago Viewed 495 times Oct 4, 2021 · We try to “aggregate” and “$lookup”, as we need to know “type” from collectionTwo, while are requesting data from collectionOne. Jul 31, 2022 · Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more. I have added one more stage in aggression to filter the service with status true. something instead of aggregate () Mar 22, 2022 · Thanks @NeNaD, that works as expected. populate is often used in the context of a schema definition in Mongoose to Apr 29, 2021 · $lookup/$unwind works, but seems to me expensive from a computational perspective. Below I have simplified the using a For more information and examples, see Field Paths. populate() to fetch those documents: Jun 8, 2016 · So as you all know, find() returns an array of results, with findOne() returning just a simply object. option() Parameters: options «Object» keys to merge into current options [options. in casts array value exists two type of casts, 1) writers and directors. Jan 12, 2022 · I have many collections in my MongoDB database. Given that: You have a collection users with a field CompanyID and a collection of companies with a field CompanyID you want to lookup Companies on Users by matching CompanyID, where additionally: each User must match condition: User. It allows you to perform complex data manipulations and transformations on MongoDB collections… Dec 10, 2018 · I have a query, that use $lookup to "join" two models, after this i use $project to select olny the fields that i need, but my $project brings an arrray of objects Jan 5, 2020 · Mongoose aggregate sort and limit on a lookup Asked 5 years, 8 months ago Modified 5 years, 8 months ago Viewed 2k times This page describes text query capabilities for self-managed (non-Atlas) deployments. multiple fields Jan 12, 2017 · I'm doing a $lookup from a _id. If you are then removing the comments from the video (as well as the actual count prop) and doing the lookup is the way to go. model('Course'). ObjectId, ref Jun 8, 2016 · Your lookup query is perfect, but the problem is you are storing incharge as string into the db, whereas the _id : ObjectId ('theID') is an Object and not just string and you cannot compare a string (' ') with an object ( { }). It provides a rich, pipeline-based approach to querying and manipulating data, which is essential for handling complex queries, aggregations, and analytics. Model. findOneAndUpdate() Model. ObjectId(id) }) . ObjectId, reviews: [{ type: mongoose. aggregate([ {"$unwind" : "$Tournament"}, {"$lookup": {"from":"Tournament", "localField":"Tournament. If yes then you can use MongoDB lookup aggregation to get the joined data using a single query. 4. aggregate() does not include a collation document, the db. aggregate() includes a collation document, that collation is used for the operation, ignoring any other collations. It helps aggregate data efficiently and is essential for situations where you need to combine related data from multiple collections. Feb 24, 2022 · Aggregate Lookup with pipeline and match not working mongodb Asked 3 years, 9 months ago Modified 3 years, 9 months ago Viewed 10k times Jul 13, 2023 · Lookup: const course = await mongoose. This i Dec 30, 2023 · Introduction Mongoose is a popular ODM library for MongoDB that provides a straightforward, schema-based solution to model your application data. 6), you can but it requires a second query, and using populate differently. Download Studio 3T to get started. I corrected the problem and edited it. However, keep in mind the solution may not work if you change your field types too far from your example documents. Aug 30, 2016 · When I do $lookup, in my case the foreignField:"_id", I get the found element in an array. now()} }) let userSchema Mongoose has a more powerful alternative called populate(), which lets you reference documents in other collections. g. Sessions are scoped to a connection, so calling mongoose. That is assuming you are not using mongoose populate to "convert" those comment ids into the referenced objects. collation]» see Aggregate. collection. I’d need to match the collections based on an exadecimal value of these owner fields, type String, that is written often in a different way. Sep 16, 2021 · I want all services in the category wise. aggregate() is run: Jun 26, 2019 · how to access field name in mongoose $aggregate->$lookup-> pipeline->$match Asked 5 years, 9 months ago Modified 5 years, 9 months ago Viewed 4k times Jan 31, 2024 · Hi all! My task is to change a query from populate () into aggregation pipeline. What is the Aggregation Framework? Syntactically, an aggregation framework query is an array of stages. Jun 24, 2020 · How does populate () in mongoose work that makes it more powerful than MongoDB's $lookup? In my opinion, there are places to use populate() and others to use $lookup. aggregate ( [ Jan 29, 2018 · when i run aggregate lookup with bellow query, in new generated lookup array only one casts contents If in accordance with above casts array value aggregate lookup should return two casts content with two type. connection. Let’s imagine 0xfba… in the first collection and on the other one 0xFBa Calling mongoose. Feb 6, 2022 · This means that every time you lookup you must convert your string ids into ObjectId or the other way around. Follow along with query examples using the most important aggregation stages, and test your skills! Nov 8, 2022 · I am trying to get specific fields from the array I got after aggregate, lookup and some cond Mar 15, 2024 · The aggregation pipelinein MongoDB is a powerful framework for data processing and transformation. The json data in the How can I use aggregate and find together in Mongoose? i. Both the fields are on the two collections are named “owner”. Use the `$lookup` aggregation stage to filter and process documents from local and foreign collections. findByIdAndRemove() Model. It's a high-level abstraction provided by Mongoose to simplify working with related documents. ObjectId, ref: "Review Use the ``$project`` aggregation stage to pass documents with specified fields to the next stage. If you don't mind, if the reports collection had say anotherTestReport similar to testReport, is it possible to use multiple unwind and lookup and add the new ids to setupIds? I tried to run the same query next time but it replaced all the ids. 2. com', user_group_ids: [ 0: 630ccd1a3a2da7d625cc7ccf ] user_groups collection Perform full-text searches in Atlas collections using the `$search` aggregation pipeline stage with MongoDB Search indexes. collation] «Object» object see Aggregate Jun 12, 2019 · So performance wise obviously the lookup would add time. _casts should contains Mar 31, 2021 · mongoose aggregate lookup with matching ObjectId Asked 3 years, 6 months ago Modified 3 years, 4 months ago Viewed 100 times Jun 5, 2021 · Krishna Bose Posted on Jun 5, 2021 MongoDB lookup on an array of objects which contains (foreign) ObjectId as a key # mongodb # programming # database Aug 19, 2020 · In Mongoose, you can perform multiple field searches using the aggregation pipeline. startSession() is equivalent to calling mongoose. In this tutorial, we’ve explored a variety of methods to achieve this, such as using query conditionals, logical operators, custom query helpers, population, and aggregation. replaceOne() Model Oct 19, 2022 · The second thing is that using an index to perform the $lookup s is important and will likely improve performance, but it may not make this operation "fast". Feb 3, 2020 · They must be same because $lookup performs an equality match on the foreignField to the localField from the input documents If you save your varyandid as Object id aggregate will work. The aggregation pipeline allows you to perform complex data transformations and queries on your MongoDB data, including searching across multiple fields. findByIdAndDelete() Model. com In mongo, after doing an aggregation with $lookup, I would like the request to return only some fields and not the whole document. I want to join three collections in MongoDB using the aggregate $lookup. . Explore $lookup operations for joins, subqueries, arrays, and more. findOneAndDelete() Model. Collection 1: article_category { "article_id": Mar 16, 2019 · Here's my aggregation. $let operátor v MongoDB umožňuje přístup k proměnným definovaným mimo jeho výrazový blok, včetně systémových proměnných. Here I defined Content schema - const ContentSchema = new Sche Dec 30, 2023 · In this guide, we explored the essentials of grouping results in Mongoose with practical examples. Aggregation work's good but I can't push some fields to the output I needed, collection A is: { _id: some mongodbID //fields items: [ { Jul 23, 2025 · Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more. 6 or later. It had a hiccup I failed to see. Aggregating with $lookup and subsequent $group is pretty cumbersome, so if (and that's a medium if) you're using node & Mongoose or a supporting library with some hints in the schema, you could use a . For data hosted on MongoDB, MongoDB also offers an improved full-text query solution, MongoDB Search and a vector search solution, Vector Search. exec () check if there are no data Asked 2 years, 6 months ago Modified 1 year, 10 months ago Viewed 976 times Aug 3, 2020 · Thanks. Apr 29, 2021 · Mongoose Aggregate with Array of Objects in $lookup Asked 3 years, 9 months ago Modified 3 years, 9 months ago Viewed 427 times If the db. User I have two collections where need to lookup on aggregate. Schema. You want to filter, transform, group, sort, and calculate data in powerful and complex ways — all within the database itself. PrizeMoney" } }} ]) But I get for every played the sum is 0. One of the most powerful features of Mongoose is the aggregate() method. Parameters options «Object» keys to merge into current options number « [options. Nov 24, 2022 · Sorry for temporarily deleting my above post, if you were around at that time. This means you will not be able to use the index on the converted values. Jul 23, 2025 · This article will dive deep into the Mongoose Aggregate API, explaining its usage, syntax, and practical examples for beginners and experienced developers alike. UserName equals administrator each Company on User must match condition: CompanyName equals edt5 The following query I'm using the aggregate method in Mongodb against a text search. MongoDB Playground Is there a way to fetch a field value from a 1-to-1 relationship Below answer is for mongoDB 3. findByIdAndUpdate() Model. Mongo version is 3. let query = mongoose. So the result is always 1 document. I am using Mongoose aggregation. I have the following query : db 请参阅以下示例： 使用$ lookup执行单一平等加入 将$ lookup与数组配合使用 将$ lookup与$ mergeObjects一起使用 Jul 23, 2025 · Mongoose, a popular ODM (Object Data Modeling) library for MongoDB and Node. It allows you to automatically replace specified paths in a document with documents from other collections. Aggregate function: Jul 3, 2018 · I am new to mongodb so I hope this does not come-off as a very elementary question. Feb 12, 2023 · Introduction: The Aggregation Pipeline in MongoDB is a strong tool that lets you handle Tagged with devmeme, watercooler. It is very slow though. findById() Model. startSession(). That's pretty straightforward where posts need to lookup comments on listing. Starting from fundamental concepts and gradually moving to advanced techniques, this tutorial has demonstrated aggregate operations within a Mongoose context using modern JavaScript features. collation () ClientSession « [options from: The collection to use for lookup in the same database localField: The field in the primary collection that can be used as a unique identifier in the from collection. something instead of aggregate () I've to write an aggregation query in MongoDB where the $lookup from source collection to destination collection can be from multiple fields. Its populate mechanism allows developers to create a reference to other documents in Learn about the $unwind aggregation stage, which deconstructs array fields to output a document for each element. I would want to only get one field from the resulting JSON not whole document. find() Model. User. It worked like expected. In mongo, after doing an aggregation with $lookup, I would like the request to return only some fields and not the whole document. I have the following query : db Dec 30, 2023 · Here, we embark on a journey through MongoDB’s $lookup operator, exploring its power and versatility through practical examples using Mongoose. May 13, 2020 · How to change my $lookup aggregation so that i have get combined records from all three collections Is this a different request where you want to join documents from three different collections, or is that a typo? Jun 15, 2020 · The lookup & group is widely used in the aggregate but when and how can it be used if there is a speed problem? Is there no way to reduce the time of lookup & count (group) query? Mar 22, 2022 · Thanks @NeNaD, that works as expected. name='abc 128 With the latest version of mongoose (mongoose >= 3. e. Then we sort by that column, then skip/limit the results to get the first 10 results. Therefore that predicate should come in a $match stage that precedes the $lookup: Aggregate. As written, this aggregation will perform a full collection scan to process all of the documents in the source collection. Think of the aggregation pipeline as MongoDB’s way of processing data records and returning computed Apr 7, 2020 · mongoose aggregate lookup give only one object Asked 4 years, 11 months ago Modified 4 years, 11 months ago Viewed 1k times May 18, 2020 · Mongoose's aggregate() function is how you use MongoDB's aggregation framework with Mongoose. prototype. lookup for joining two tables and i am not able to get the collection of records. aggregate() or aggregate Update Documents Using an Aggregation Pipeline To update documents with an aggregation pipeline, use: Jun 21, 2019 · Continue to help good content that is interesting, well-researched, and useful, rise to the top! To gain full voting privileges, Nov 22, 2022 · The friend_id field is present in the friendRequests collection (source for the aggregation) not the users collection which is the target for the $lookup. Upvoting indicates when questions and answers are useful. Mongoose models provide several static helper functions for CRUD operations. aggregate pipeline. because mongoDB automatically assigns plural words to collection names. What is the Mongoose Aggregate () Method? The Mongoose Aggregate () method is used to execute aggregation pipelines on MongoDB collections. If the db. May 20, 2022 · Hi everyone, I’m struggling with a query lookup with two collections where I’m comparing strings of owners. See full list on mongoosejs. Apr 8, 2019 · The populate() functionality in Mongoose is a client-side query aggregation feature that predates the addition of server-side $lookup support in MongoDB 3. The Pet schema has information that I want to $sum inside the User. wnwfi tmx pqb qduyfom gehhlz hpz vjm xirsty wqpew quoi sskxawr rrwo qfd eetl dkauj