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Bulk Write Operations

On this page

  • Overview
  • Sample Data
  • Define the Write Operations
  • Insert Operations
  • Update Operations
  • Replace Operations
  • Delete Operations
  • Run the Write Operations
  • Customize Bulk Write Operations
  • Return Value
  • Handling Exceptions
  • Additional Information

This guide shows you how to use the .NET/C# Driver to perform bulk write operations from your MongoClient instance. A bulk write operation is a single database call that performs multiple write operations on one or more MongoDB collections. This is more efficient than performing multiple individual write operations because it reduces the number of round trips between your application and the database.

The examples in this guide use the sample_restaurants.restaurants collection from the Atlas sample datasets. To learn how to create a free MongoDB Atlas cluster and load the sample datasets, see the Quick Start tutorial.

For each write operation you want to perform, create an instance of one of the following BulkWriteModel classes:

  • BulkWriteInsertOneModel<TDocument>

  • BulkWriteUpdateOneModel<TDocument>

  • BulkWriteUpdateManyModel<TDocument>

  • BulkWriteReplaceOneModel<TDocument>

  • BulkWriteDeleteOneModel<TDocument>

  • BulkWriteDeleteManyModel<TDocument>

The following sections show how to create and use instances of the preceding classes to perform the corresponding write operation in a bulk write.

Tip

Bulk Write Operations with POCOs

The examples in this guide use the BsonDocument type for the TDocument type in all generic classes. You can also use a Plain Old CLR Object (POCO) for these classes. To do so, you must define a class that represents the documents in your collection. The class must have properties that match the fields in your documents. For more information, see POCOs.

To perform an insert operation, create an instance of the BulkWriteInsertOneModel<TDocument> class. The BulkWriteInsertOneModel<TDocument> constructor accepts the following parameters:

Parameter
Description
collectionNamespace
document
The document to insert into the collection.

Data Type: TDocument

The following example creates an instance of the BulkWriteInsertOneModel<TDocument> class. This instance directs the driver to insert a document in which the "name" field is "Mongo's Deli" into the sample_restaurants.restaurants collection.

var insertOneModel = new BulkWriteInsertOneModel<BsonDocument>(
"sample_restaurants.restaurants",
new BsonDocument{
{ "name", "Mongo's Deli" },
{ "cuisine", "Sandwiches" },
{ "borough", "Manhattan" },
{ "restaurant_id", "1234" }
}
);

Tip

Insert Multiple Documents

To insert multiple documents, create an instance of the BulkWriteInsertOneModel<TDocument> class for each document you want to insert.

To update a single document, create an instance of the BulkWriteUpdateOneModel<TDocument> class. The BulkWriteUpdateOneModel<TDocument> constructor accepts the following parameters:

Parameter
Description
collectionNamespace
The database and collection to insert the BSON document into.

Data Type: string or CollectionNamespace
filter
The query filter that specifies the criteria used to match documents in your collection. The UpdateOne operation updates only the first document that matches the query filter.

update
The update operation you want to perform. For more information about update operations, see Field Update Operators in the MongoDB Server manual.

collation
Optional. The language collation to use when sorting results. See the {+mdb+server+} manual for more information.

Data Type: Collation
Default: null
hint
Optional. The index to use to scan for documents. See the MongoDB Server manual for more information.

Data Type: BsonValue
Default: null
isUpsert
Optional. Specifies whether the update operation performs an upsert operation if no documents match the query filter. See the MongoDB Server manual for more information.

Data Type: boolean
Default: false
arrayFilters
Specifies which array elements to modify for an update operation on an array field. See the MongoDB Server manual for more information.

Default: null

In the following code example, the BulkWriteUpdateOneModel<BsonDocument> object represents an update operation on the sample_restaurants.restaurants collection. The operation matches the first document in the collection where the value of the name field is "Mongo's Deli". It then updates the value of the cuisine field in the matched document to "Sandwiches and Salads".

var updateOneModel = new BulkWriteUpdateOneModel<BsonDocument>(
"sample_restaurants.restaurants",
Builders<BsonDocument>.Filter.Eq("name", "Mongo's Deli"),
Builders<BsonDocument>.Update.Set("cuisine", "Sandwiches and Salads")
);

To update multiple documents, create an instance of the BulkWriteUpdateManyModel<TDocument> class. The constructor for this class accepts the same parameters as the BulkWriteUpdateOneModel<TDocument> constructor. The BulkWriteUpdateManyModel<TDocument> operation updates all documents that match your query filter.

In the following code example, the BulkWriteUpdateManyModel<BsonDocument> object represents an update operation on the sample_restaurants.restaurants collection. The operation matches all documents in the collection where the value of the name field is "Mongo's Deli". It then updates the value of the cuisine field to "Sandwiches and Salads".

var updateManyModel = new BulkWriteUpdateManyModel<BsonDocument>(
"sample_restaurants.restaurants",
Builders<BsonDocument>.Filter.Eq("name", "Mongo's Deli"),
Builders<BsonDocument>.Update.Set("cuisine", "Sandwiches and Salads")
);

To replace the fields in a document, create an instance of the BulkWriteReplaceOneModel<TDocument> class. The BulkWriteReplaceOneModel<TDocument> constructor accepts the following parameters:

Parameter
Description
collectionNamespace
The database and collection to insert the BSON document into.

Data Type: string or CollectionNamespace
filter
The query filter that specifies the criteria used to match documents in your collection. The UpdateOne operation updates only the first document that matches the query filter.

replacement
The replacement document, which specifies the fields and values to insert in the target document.

Data Type: TDocument
collation
Optional. The language collation to use when sorting results. See the MongoDB Server manual for more information.

Data Type: Collation
Default: null
hint
Optional. The index to use to scan for documents. See the MongoDB Server manual for more information.

Data Type: BsonValue
Default: null
isUpsert
Optional. Specifies whether the update operation performs an upsert operation if no documents match the query filter. See the MongoDB Server manual for more information.

Data Type: boolean
Default: false

In the following example, the BulkWriteReplaceOneModel<BsonDocument> object represents a replace operation on the sample_restaurants.restaurants collection. The operation matches the document in the collection where the value of the restaurant_id field is "1234". It then removes all fields other than _id from this document, and sets new values in the name, cuisine, borough, and restaurant_id fields.

var replaceOneModel = new BulkWriteReplaceOneModel<BsonDocument>(
"sample_restaurants.restaurants",
Builders<BsonDocument>.Filter.Eq("restaurant_id", "1234"),
new BsonDocument{
{ "name", "Mongo's Pizza" },
{ "cuisine", "Pizza" },
{ "borough", "Brooklyn" },
{ "restaurant_id", "5678" }
}
);

Tip

Replace Multiple Documents

To replace multiple documents, create an instance of the BulkWriteReplaceOneModel<TDocument> class for each document you want to replace.

To delete a document, create an instance of the BulkWriteDeleteOneModel<TDocument> class. The BulkWriteDeleteOneModel<TDocument> constructor accepts the following parameters:

Parameter
Description
collectionNamespace
The database and collection to insert the BSON document into.

Data Type: string or CollectionNamespace
filter
The query filter that specifies the criteria used to match documents in your collection. The DeleteOne operation deletes only the first document that matches the query filter.

collation
Optional. The language collation to use when sorting results. See the MongoDB Server manual for more information.

Data Type: Collation
Default: null
hint
Optional. The index to use to scan for documents. See the MongoDB Server manual for more information.

Data Type: BsonValue
Default: null

In the following code example, the BulkWriteDeleteOneModel<BsonDocument> object represents a delete operation on the sample_restaurants.restaurants collection. The operation matches and deletes the first document where the value of the restaurant_id field is "5678".

var deleteOneModel = new BulkWriteDeleteOneModel<BsonDocument>(
"sample_restaurants.restaurants",
Builders<BsonDocument>.Filter.Eq("restaurant_id", "5678")
);

To delete multiple documents, create an instance of the BulkWriteDeleteManyModel<TDocument> class and pass a query filter that specifies the document that you want to delete. The DeleteMany operation removes all documents that match your query filter.

In the following code example, the BulkWriteDeleteManyModel<BsonDocument> object represents a delete operation on the sample_restaurants.restaurants collection. The operation matches and deletes all documents where the value of the name field is "Mongo's Deli".

var deleteManyModel = new BulkWriteDeleteManyModel<BsonDocument>(
"sample_restaurants.restaurants",
Builders<BsonDocument>.Filter.Eq("name", "Mongo's Deli")
);

After you define a BulkWriteModel instance for each operation that you want to perform, create an instance of a class that implements the IReadOnlyList interface. Add your BulkWriteModel objects to this IReadOnlyList, then pass the IReadOnlyList to the BulkWrite() or BulkWriteAsync() method. By default, these methods run the operations in the order they're defined in the collection.

Tip

IReadOnlyList

Array and List are two common classes that implement the IReadOnlyList interface.

Select from the following tabs to view how to use the asynchronous BulkWriteAsync() method and the synchronous BulkWrite() method to perform a bulk write operation.

var client = new MongoClient("mongodb://localhost:27017");
var collection = "sample_restaurants.restaurants";
var bulkWriteModels = new[]
{
new BulkWriteInsertOneModel<BsonDocument>(
collection,
new BsonDocument{
{ "name", "Mongo's Deli" },
{ "cuisine", "Sandwiches" },
{ "borough", "Manhattan" },
{ "restaurant_id", "1234" }
}
),
new BulkWriteInsertOneModel<BsonDocument>(
collection,
new BsonDocument{
{ "name", "Mongo's Deli" },
{ "cuisine", "Sandwiches" },
{ "borough", "Brooklyn" },
{ "restaurant_id", "5678" }
}
),
new BulkWriteUpdateManyModel<BsonDocument>(
collection,
Builders<BsonDocument>.Filter.Eq("name", "Mongo's Deli"),
Builders<BsonDocument>.Update.Set("cuisine", "Sandwiches and Salads")
),
new BulkWriteDeleteOneModel<BsonDocument>(
collection,
Builders<BsonDocument>.Filter.Eq("restaurant_id", "1234")
)
};
var results = await client.BulkWriteAsync(bulkWriteModels);
Console.WriteLine("Bulk write results: " + results);
var client = new MongoClient("mongodb://localhost:27017");
var collection = "sample_restaurants.restaurants";
var bulkWriteModels = new[]
{
new BulkWriteInsertOneModel<BsonDocument>(
collection,
new BsonDocument{
{ "name", "Mongo's Deli" },
{ "cuisine", "Sandwiches" },
{ "borough", "Manhattan" },
{ "restaurant_id", "1234" }
}
),
new BulkWriteInsertOneModel<BsonDocument>(
collection,
new BsonDocument{
{ "name", "Mongo's Deli" },
{ "cuisine", "Sandwiches" },
{ "borough", "Brooklyn" },
{ "restaurant_id", "5678" }
}
),
new BulkWriteUpdateManyModel<BsonDocument>(
collection,
Builders<BsonDocument>.Filter.Eq("name", "Mongo's Deli"),
Builders<BsonDocument>.Update.Set("cuisine", "Sandwiches and Salads")
),
new BulkWriteDeleteOneModel<BsonDocument>(
collection,
Builders<BsonDocument>.Filter.Eq("restaurant_id", "1234")
)
};
var results = client.BulkWrite(bulkWriteModels);
Console.WriteLine("Bulk write results: " + results);

The preceding code examples produce the following output:

BulkWriteResult({'writeErrors': [], 'writeConcernErrors': [], 'nInserted': 2, 'nUpserted': 0, 'nMatched': 2, 'nModified': 2, 'nRemoved': 1, 'upserted': []}, acknowledged=True)

When you call the BulkWrite() or BulkWriteAsync() method, you can pass an instance of the ClientBulkWriteOptions class. The ClientBulkWriteOptions class contains the following properties, which represent options you can use to configure the bulk write operation:

Property
Description
BypassDocumentValidation
Specifies whether the operation bypasses document-level validation. For more information, see Schema Validation in the MongoDB Server manual.
Defaults to false.
Comment
A comment to attach to the operation, in the form of a BsonValue. For more information, see the delete command fields guide in the MongoDB Server manual.
IsOrdered
If true, the driver performs the write operations in the order provided. If an error occurs, the remaining operations are not attempted.

If false, the driver performs the operations in an arbitrary order and attempts to perform all operations. If any of the write operations in an unordered bulk write fail, the driver reports the errors only after attempting all operations.
Defaults to True.
Let
A map of parameter names and values, in the form of a BsonDocument. Values must be constant or closed expressions that don't reference document fields. For more information, see the let statement in the MongoDB Server manual.
VerboseResult
Specifies whether the ClientBulkWriteResult object returned by the operation includes detailed results for each successful write operation.
Defaults to false.
WriteConcern
The write concern to use for the write operation, as a value from the WriteConcern enum.
Defaults to the write concern of the collection on which the operation is running.

The following code examples use a ClientBulkWriteOptions object to customize a delete operation:

var client = new MongoClient("mongodb://localhost:27017");
var deleteOneModel = new BulkWriteDeleteOneModel<BsonDocument>(
"sample_restaurants.restaurants",
Builders<BsonDocument>.Filter.Eq("restaurant_id", "5678")
);
var clientBulkWriteOptions = new ClientBulkWriteOptions
{
IsOrdered = false,
WriteConcern = WriteConcern.Unacknowledged,
VerboseResult = true
};
var results = await client.BulkWriteAsync(deleteOneModel, clientBulkWriteOptions);
var client = new MongoClient("mongodb://localhost:27017");
var deleteOneModel = new BulkWriteDeleteOneModel<BsonDocument>(
"sample_restaurants.restaurants",
Builders<BsonDocument>.Filter.Eq("restaurant_id", "5678")
);
var clientBulkWriteOptions = new ClientBulkWriteOptions
{
IsOrdered = false,
WriteConcern = WriteConcern.Unacknowledged,
VerboseResult = true
};
var results = client.BulkWrite(deleteOneModel, clientBulkWriteOptions);

The BulkWrite() and BulkWriteAsync() methods return a ClientBulkWriteResult object that contains the following properties:

Property
Description
Acknowledged
Indicates whether the server acknowledged the bulk write operation. If the value of this property is false and you try to access any other property of the ClientBulkWriteResult object, the driver throws an exception.
DeleteResults
An IReadOnlyDictionary<int, BulkWriteDeleteResult> object containing the results of each successful delete operation, if any.
DeletedCount
The number of documents deleted, if any.
InsertResults
An IReadOnlyDictionary<int, BulkWriteInsertOneResult> object containing the results of each successful insert operation, if any.
InsertedCount
The number of documents inserted, if any.
MatchedCount
The number of documents matched for an update, if applicable.
ModifiedCount
The number of documents modified, if any.
UpsertResults
An IReadOnlyDictionary<int, BulkWriteUpdateResult> object containing the results of each successful update operation, if any.
UpsertedCount
The number of documents upserted, if any.

If any of the operations in a bulk write operation fail, the .NET/C# Driver throws a ClientBulkWriteException and does not perform any further operations.

A ClientBulkWriteException object contains the following properties:

Property
Description
connectionId
The connection identifier.

Data Type: ConnectionId
message
The error message.

Data Type: string
writeErrors
A dictionary of errors that occurred during the bulk write operation.

Data Type: IReadOnlyDictionary<int, WriteError>
partialResult
The results of any successful operations performed before the exception was thrown.

writeConcernErrors
Write concern errors that occurred during execution of the bulk write operation.

Data Type: IReadOnlyList<MongoWriteConcernException>
innerException
The inner exception.

Data Type: Exception

To learn how to perform individual write operations, see the following guides:

To learn more about any of the methods or types discussed in this guide, see the following API documentation:

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