Update Single Document in Collection in MongoDB

Update Single Document in Collection in MongoDB

Introduction:
Updating a single document in a MongoDB collection allows you to modify specific fields or properties of an existing document. MongoDB provides various methods to perform updates, giving you flexibility in how you want to update your data.

Prerequisites:
Before we proceed, ensure that you have the following in place:

1. MongoDB installed on your system.
2. A database and a collection created in MongoDB.

Method 1: Using updateOne()

The updateOne() method in MongoDB allows you to update a single document that matches a specified filter.

Syntax:

javascript
db.collection.updateOne(
   <filter>,
   <update>,
   <options>
)

Parameters:

• <filter>: Specifies the filter criteria to match the document(s) you want to update.
• <update>: Specifies the update operations and the new values to set.
• <options>: (Optional) Specifies additional options like upsert (insert if not found) and array filters.

Example:
Let's say we have a collection called "users," and we want to update the age of a user with name "John."

javascript
// Connect to the database
const { MongoClient } = require('mongodb');
const uri = 'mongodb://localhost:27017';
const client = new MongoClient(uri);

async function updateSingleDocument() {
  try {
    await client.connect();
    const database = client.db('yourDatabaseName');
    const collection = database.collection('users');

    const filter = { name: 'John' };
    const update = { $set: { age: 30 } };

    const result = await collection.updateOne(filter, update);

    console.log(`${result.matchedCount} document(s) matched the filter.`);
    console.log(`${result.modifiedCount} document(s) updated.`);
  } catch (err) {
    console.log('Error: ', err);
  } finally {
    // Close the connection
    client.close();
  }
}

updateSingleDocument();

Explanation:
In this example, we use the updateOne() method to update the age of the user with the name "John." The filter { name: 'John' } ensures that we target only the document(s) that match this condition. The update operation $set is used to update the "age" field to 30.

Method 2: Using findOneAndUpdate()

The findOneAndUpdate() method is similar to updateOne() but also returns the updated document.

Syntax:

javascript
db.collection.findOneAndUpdate(
   <filter>,
   <update>,
   <options>
)

Parameters:

• <filter>: Specifies the filter criteria to match the document(s) you want to update.
• <update>: Specifies the update operations and the new values to set.
• <options>: (Optional) Specifies additional options like sort and returnOriginal.

Example:
Let's consider the same "users" collection and update John's age using findOneAndUpdate().

javascript
// Connect to the database (assuming 'users' collection and 'yourDatabaseName' database)
async function updateSingleDocumentFindOneAndUpdate() {
  try {
    await client.connect();
    const database = client.db('yourDatabaseName');
    const collection = database.collection('users');

    const filter = { name: 'John' };
    const update = { $set: { age: 30 } };
    const options = { returnOriginal: false };

    const updatedDocument = await collection.findOneAndUpdate(filter, update, options);

    console.log('Updated Document: ', updatedDocument.value);
  } catch (err) {
    console.log('Error: ', err);
  } finally {
    // Close the connection
    client.close();
  }
}

updateSingleDocumentFindOneAndUpdate();

Explanation:
In this example, we use the findOneAndUpdate() method to update the age of the user with the name "John." The returnOriginal: false option ensures that the method returns the updated document instead of the original one.

Conclusion:
Updating a single document in a MongoDB collection is a common operation in database management. MongoDB provides several methods, such as updateOne() and findOneAndUpdate(), to accomplish this task based on your specific requirements. By leveraging these methods, you can efficiently update data within your MongoDB collections.