How to use limit operator in MongoDB?

Data Science, AI and ML
1

MongoDB limit() Method

In MongoDB, limit() method is used to limit the fields of document that you want to show. Sometimes, you have a lot of fields in collection of your database and have to retrieve only 1 or 2. In such case, limit() method is used.

The MongoDB limit() method is used with find() method.

Syntax:

db.COLLECTION_NAME.find().limit(NUMBER)

Scenario:

Consider an example which has a collection name javatpoint.

This collection has following fields within it.

[  
  {  
    Course: "Java",  
    details: { Duration: "6 months", Trainer: "Sonoo Jaiswal" },  
    Batch: [ { size: "Medium", qty: 25 } ],  
    category: "Programming Language"  
  },  
  {  
    Course: ".Net",  
    details: { Duration: "6 months", Trainer: "Prashant Verma" },  
    Batch: [ { size: "Small", qty: 5 }, { size: "Medium", qty: 10 }, ],  
    category: "Programming Language"  
  },  
  {  
    Course: "Web Designing",  
    details: { Duration: "3 months", Trainer: "Rashmi Desai" },  
    Batch: [ { size: "Small", qty: 5 }, { size: "Large", qty: 10 } ],  
    category: "Programming Language"  
  }  
];

Here, you have to display only one field by using limit() method.

Example

`

db.javatpoint.find().limit(1)

`

After the execution, you will get the following result

Output:

{ "_id" : ObjectId("564dbced8e2c097d15fbb601"), "Course" : "Java", "details" : {
 "Duration" : "6 months", "Trainer" : "Sonoo Jaiswal" }, "Batch" : [ { "size" :
"Medium", "qty" : 25 } ], "category" : "Programming Language" } 

[  
  {  
    Course: "Java",  
    details: { Duration: "6 months", Trainer: "Sonoo Jaiswal" },  
    Batch: [ { size: "Medium", qty: 25 } ],  
    category: "Programming Language"  
  },  
  {  
    Course: ".Net",  
    details: { Duration: "6 months", Trainer: "Prashant Verma" },  
    Batch: [ { size: "Small", qty: 5 }, { size: "Medium", qty: 10 }, ],  
    category: "Programming Language"  
  },  
  {  
    Course: "Web Designing",  
    details: { Duration: "3 months", Trainer: "Rashmi Desai" },  
    Batch: [ { size: "Small", qty: 5 }, { size: "Large", qty: 10 } ],  
    category: "Programming Language"  
  }  
];

Execute the following query to retrieve only one document and skip 2 documents.

Example

db.javatpoint.find().limit(1).skip(2)

After the execution, you will get the following result

Output:

{ "_id" : ObjectId("564dbced8e2c097d15fbb603"), "Course" : "Web Designing", "det
ails" : { "Duration" : "3 months", "Trainer" : "Rashmi Desai" }, "Batch" : [ { "
size" : "Small", "qty" : 5 }, { "size" : "Large", "qty" : 10 } ], "category" : "
Programming Language" }

As you can see, the skip() method has skipped first and second documents and shows only third document.