Limit number of values in a field using MongoDB?

To limit number of values in a field, use $slice operator.

Let us first create a collection with documents −

> db.numberOfValuesDemo.insertOne({"Values":[100,200,300,900,1000,98]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cefb736ef71edecf6a1f6ab")
}

Display all documents from a collection with the help of find() method −

> db.numberOfValuesDemo.find().pretty();

Output

{
   "_id" : ObjectId("5cefb736ef71edecf6a1f6ab"),
   "Values" : [
      100,
      200,
      300,
      900,
      1000,
      98
   ]
}

Following is the query to limit number of values in a field using MongoDB −

> db.numberOfValuesDemo.find({},{ "Values": { "$slice": 2 } } );

Output

{ "_id" : ObjectId("5cefb736ef71edecf6a1f6ab"), "Values" : [ 100, 200 ] }

Ankith Reddy

Published on 14-Jun-2019 10:52:32

• Related Questions & Answers
• Limit number of values in a field with MongoDB?
• MongoDB query to limit the returning values of a field?
• Limit the number of documents in a collection in MongoDB?
• List all values of a certain field in MongoDB?
• Get the duplicate values of a field in MongoDB?
• How to limit the amount of characters returned from a field in a MongoDB?
• MongoDB Aggregate to limit the number of records
• How to count number of distinct values per field/ key in MongoDB?
• How to limit the amount of characters returned from a field in a MongoDB query?
• Update MongoDB field using value of another field?
• Fetch specific field values in MongoDB
• Find all the non-distinct values of a field in MongoDB?
• Get a count of total documents with MongoDB while using limit?
• How to compare field values in MongoDB?
• How to limit the number of records, while retrieving data from a MongoDB collection using Java?