> For the complete MongoDB documentation index, see www.mongodb.com/docs/llms.txt

# Update Documents

The MongoDB shell provides the following methods to update documents in a collection:

- To update a single document, use [`db.collection.updateOne()`.](https://www.mongodb.com/docs/manual/reference/method/db.collection.updateOne.md#mongodb-method-db.collection.updateOne)

- To update multiple documents, use [`db.collection.updateMany()`.](https://www.mongodb.com/docs/manual/reference/method/db.collection.updateMany.md#mongodb-method-db.collection.updateMany)

- To replace a document, use [`db.collection.replaceOne()`.](https://www.mongodb.com/docs/manual/reference/method/db.collection.replaceOne.md#mongodb-method-db.collection.replaceOne)

The examples on this page reference the MongoDB [sample dataset](https://www.mongodb.com/docs/atlas/sample-data/). To learn more about setting up deployments and populate a cluster with the sample data, see [Get Started with MongoDB.](https://www.mongodb.com/docs/get-started.md#std-label-unified-get-started)

## Update Operator Syntax

To update a document, MongoDB provides [update operators](https://www.mongodb.com/docs/manual/reference/mql/update.md#std-label-update-operators-ref), such as [`$set`](https://www.mongodb.com/docs/manual/reference/operator/update/set.md#mongodb-update-up.-set), to modify field values.

To use the update operators, pass to the update methods an update document of the form:

```javascript
{
  <update operator>: { <field1>: <value1>, ... },
  <update operator>: { <field2>: <value2>, ... },
  ...
}
```

Some update operators, such as [`$set`](https://www.mongodb.com/docs/manual/reference/operator/update/set.md#mongodb-update-up.-set), create the field if the field does not exist. See the individual [update operators](https://www.mongodb.com/docs/manual/reference/mql/update.md#std-label-update-operators-ref) reference for details.

## Update a Single Document

Use the [`db.collection.updateOne()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.updateOne.md#mongodb-method-db.collection.updateOne) method to update the *first* document that matches a specified filter.

**Note:**

MongoDB preserves a natural sort order for documents. This ordering is an internal implementation feature, and you should not rely on any particular structure within it. To learn more, see [natural order.](https://www.mongodb.com/docs/manual/reference/glossary.md#std-term-natural-order)

**Example:**

To update the *first* document in the `sample_mflix.movies` collection where `title` equals `"Twilight"`:

```javascript
use sample_mflix

db.movies.updateOne( { title: "Twilight" },
{
  $set: {
    plot: "A teenage girl risks everything–including her life–when she falls in love with a vampire."
  },
  $currentDate: { lastUpdated: true }
})
```

The update operation:

- Uses the [`$set`](https://www.mongodb.com/docs/manual/reference/operator/update/set.md#mongodb-update-up.-set) operator to update the value of the `plot` field for the movie `Twilight`.

- Uses the [`$currentDate`](https://www.mongodb.com/docs/manual/reference/operator/update/currentDate.md#mongodb-update-up.-currentDate) operator to update the value of the `lastUpdated` field to the current date. If `lastUpdated` field does not exist, [`$currentDate`](https://www.mongodb.com/docs/manual/reference/operator/update/currentDate.md#mongodb-update-up.-currentDate) will create the field. See [`$currentDate`](https://www.mongodb.com/docs/manual/reference/operator/update/currentDate.md#mongodb-update-up.-currentDate) for details.

## Update Multiple Documents

Use the [`db.collection.updateMany()`](https://www.mongodb.com/docs/manual/reference/method/db.collection.updateMany.md#mongodb-method-db.collection.updateMany) to update all documents that match a specified filter.

**Example:**

To update all documents in the `sample_airbnb.listingsAndReviews` collection to update where `security_deposit` is less than `100`:

```javascript
use sample_airbnb

db.listingsAndReviews.updateMany(
  { security_deposit: { $lt: 100 } },
  {
    $set: { security_deposit: 100, minimum_nights: 1 }
  }
)
```

The update operation uses the [`$set`](https://www.mongodb.com/docs/manual/reference/operator/update/set.md#mongodb-update-up.-set) operator to update the value of the `security_deposit` field to `100` and the value of the `minimum_nights` field to `1`.

## Replace a Document

To replace the entire content of a document except for the `_id` field, pass an entirely new document as the second argument to [`db.collection.replaceOne()`.](https://www.mongodb.com/docs/manual/reference/method/db.collection.replaceOne.md#mongodb-method-db.collection.replaceOne)

When replacing a document, the replacement document must contain only field/value pairs. Do not include [update operators](https://www.mongodb.com/docs/manual/reference/mql/update.md#std-label-update-operators-ref) expressions.

The replacement document can have different fields from the original document. In the replacement document, you can omit the `_id` field since the `_id` field is immutable; however, if you do include the `_id` field, it must have the same value as the current value.

**Example:**

To replace the *first* document from the `sample_analytics.accounts` collection where `account_id: 371138`:

```javascript
db.accounts.replaceOne(
  { account_id: 371138 },
  { account_id: 893421, limit: 5000, products: [ "Investment", "Brokerage" ] }
)
```

Run the following command to read your updated document:

```javascript
db.accounts.findOne( { account_id: 893421 } )
```

## Update Behavior

To learn more about the specific behavior of updating documents, see [Behavior.](https://www.mongodb.com/docs/manual/tutorial/update-documents.md#std-label-write-op-update-behavior)

## Learn More

- To learn how to update documents using an aggregation pipeline, see [Updates with Aggregation Pipeline.](https://www.mongodb.com/docs/manual/tutorial/update-documents-with-aggregation-pipeline.md#std-label-updates-agg-pipeline)

- To see all available methods to update documents, see [Update Methods.](https://www.mongodb.com/docs/manual/reference/update-methods.md#std-label-update-methods)