What is ({$natural: 1}) in MongoDB?

The {$natural: 1} is a MongoDB sort option that returns documents in their natural insertion order. When used with {$natural: -1}, it works like LIFO (Last In First Out), showing the most recently inserted document first.

Syntax

db.collection.find().sort({$natural: 1});   // Insertion order
db.collection.find().sort({$natural: -1});  // Reverse insertion order

Sample Data

Let us create a collection with documents ?

db.demo614.insertMany([
    {"CountryName": "US"},
    {"CountryName": "UK"},
    {"CountryName": "AUS"},
    {"CountryName": "IND"}
]);

{
    "acknowledged": true,
    "insertedIds": [
        ObjectId("5e988cddf6b89257f5584d8e"),
        ObjectId("5e988ce0f6b89257f5584d8f"),
        ObjectId("5e988ce3f6b89257f5584d90"),
        ObjectId("5e988cebf6b89257f5584d91")
    ]
}

Example 1: Natural Order ({$natural: 1})

Display documents in their natural insertion order ?

db.demo614.find().sort({$natural: 1});

{ "_id": ObjectId("5e988cddf6b89257f5584d8e"), "CountryName": "US" }
{ "_id": ObjectId("5e988ce0f6b89257f5584d8f"), "CountryName": "UK" }
{ "_id": ObjectId("5e988ce3f6b89257f5584d90"), "CountryName": "AUS" }
{ "_id": ObjectId("5e988cebf6b89257f5584d91"), "CountryName": "IND" }

Example 2: Reverse Natural Order ({$natural: -1})

Display documents in reverse insertion order (LIFO) ?

db.demo614.find().sort({$natural: -1});

{ "_id": ObjectId("5e988cebf6b89257f5584d91"), "CountryName": "IND" }
{ "_id": ObjectId("5e988ce3f6b89257f5584d90"), "CountryName": "AUS" }
{ "_id": ObjectId("5e988ce0f6b89257f5584d8f"), "CountryName": "UK" }
{ "_id": ObjectId("5e988cddf6b89257f5584d8e"), "CountryName": "US" }

Key Points

• {$natural: 1} returns documents in the order they were inserted
• {$natural: -1} returns documents in reverse insertion order
• This sort method is useful for time-based queries when you need chronological ordering

Conclusion

The $natural sort option provides an efficient way to retrieve documents based on their insertion order. Use -1 for LIFO behavior to get the most recent documents first.