How to Insert Document in MongoDB: Syntax and Examples

To insert a document in MongoDB, use the insertOne() method on a collection, passing the document as an object. This adds the document to the collection and returns an acknowledgment with the inserted ID.

Syntax

The basic syntax to insert a single document into a MongoDB collection is:

• db.collection.insertOne(document): Inserts one document into the collection.
• document: A JSON-like object representing the data to insert.

This method returns an object containing the insertedId of the new document.

mongodb

db.collection.insertOne({ key: "value" })

Example

This example shows how to insert a document with a name and age into a users collection.

mongodb

use testdb

db.users.insertOne({ name: "Alice", age: 30 })

Output

{ "acknowledged" : true, "insertedId" : ObjectId("someObjectId") }

Common Pitfalls

Common mistakes when inserting documents include:

• Forgetting to use insertOne() or using insert() which is deprecated.
• Passing invalid document formats (must be JSON-like objects).
• Not connecting to the correct database or collection before inserting.

Always check the returned acknowledgment to confirm the insert succeeded.

mongodb

/* Wrong: using deprecated insert() */
db.users.insert({ name: "Bob" })

/* Right: use insertOne() */
db.users.insertOne({ name: "Bob" })

Quick Reference

Remember these tips when inserting documents:

• Use insertOne() for single documents.
• Use insertMany() for multiple documents.
• Documents must be valid JSON-like objects.
• Check the insert acknowledgment for success.

Key Takeaways

Use insertOne() to add a single document to a MongoDB collection.

Pass a valid JSON-like object as the document to insert.

Check the returned acknowledgment to confirm successful insertion.

Avoid deprecated methods like insert() for inserting documents.

Ensure you are connected to the correct database and collection before inserting.