MongoDB limit() - Querying and Projection

MongoDB's limit() method is used to limit the number of documents returned by a query. When the limit() method is applied to a MongoDB query, it specifies the maximum number of documents that should be returned from the query.

Syntax

The syntax for the limit() method is as follows:

db.collection.find().limit(number_of_documents)

Here, db.collection.find() represents the query to be executed and number_of_documents is the maximum number of documents that should be returned from the query.

Example

Suppose we have the following collection named students in our MongoDB database:

{
  "_id": 1,
  "name": "John",
  "age": 25
},
{
  "_id": 2,
  "name": "Jane",
  "age": 22
},
{
  "_id": 3,
  "name": "Bob",
  "age": 30
},
{
  "_id": 4,
  "name": "Alice",
  "age": 26
},
{
  "_id": 5,
  "name": "Henry",
  "age": 35
}

To limit the number of documents returned by a query to a maximum of 3 documents, we can execute the following query:

db.students.find().limit(3)

This will return the first three documents from the students collection:

{
  "_id": 1,
  "name": "John",
  "age": 25
},
{
  "_id": 2,
  "name": "Jane",
  "age": 22
},
{
  "_id": 3,
  "name": "Bob",
  "age": 30
}

Output

The limit() method limits the number of documents returned by a query. When applied to a MongoDB query, it specifies the maximum number of documents that should be returned from the query. The output is the set of documents that satisfy the query with the limit() parameter applied.

Explanation

The limit() method is used to restrict the number of documents returned by a query. It can be used to optimize queries and improve query execution times. A common use case is where the user wants to display only a certain number of documents on a page and requires pagination.

Use

The limit() method is useful for queries where only a specific number of documents are required to be returned. It reduces the size of data transferred from the database to the application and improves query performance.

Important Points

• The limit() method specifies the maximum number of documents that should be returned from a query.
• The limit() method can be used to optimize queries and improve query execution times.
• limit() is used in conjunction with other query operators such as find(), sort(), and skip().

Summary

In this page, we learned about the limit() method in MongoDB. It is used to limit the number of documents returned by a query. The limit() method is useful for queries where only a specific number of documents are required to be returned and improves query performance. We discussed the syntax, example, output, explanation, use, and important points of the limit() method.