Different Methods in MongoDB to Query Array Elements
MongoDB provides a variety of methods to access and query array elements within the documents.
| Method | Definition | Syntax |
|---|---|---|
| Query using dot notation | dot notation to access an element by its index in the array. | db.collection.find({“arrayName.index”: “value”}) |
| Query using $elemMatch | $elemMatch operator matches documents that contain an array with at least one element that matches the specified query criteria. | db.collection.find({ <arrayField>:{$elemMatch: {<query>}}) |
| Query using $slice | The $slice is a projection operator in MongoDB that limits the number of elements from an array to return in the results. | db.collection.find( {}, {arrayName: { $slice: 5 }}) |
| Unwinding | Unwinding allows users in MongoDB to output a document for each element in the array. This makes it easier for the developers to run aggregation queries on the array data. | db.collection.aggregate([{$unwind: “$arrayName”}]) |
MongoDB Query an Array
MongoDB is an open-source document, NoSQL database that stores the data in a document-oriented structure. With the help of MongoDB, we can handle large, complex, and unstructured data efficiently because MongoDB is widely used for Scalability and Flexibility.
In this article, we will learn about the Array Element and How to query array elements in MongoDB and perform various queries to get an exceptional understanding of Array elements in MongoDB.