Delete a document (C#)
Finds a single document in a collection using filter and sort clauses, and then deletes that document.
This method and the method to find and delete a document have the same database effect but differ in their return value. This method returns details about the success of the deletion. The method to find and delete a document returns the document that was found and deleted.
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Ready to write code? See the examples for this method to get started. If you are new to the Data API, check out the quickstart. |
Result
Deletes a document that matches the specified parameters and returns a DeleteResult object, which includes the number of documents that were deleted.
Parameters
Use the DeleteOneAsync method, which belongs to the Collection class.
You can also use DeleteOne, which is the synchronous version of the method.
Method signature
public Task<DeleteResult> DeleteOneAsync(
CollectionFilter<T> filter,
CollectionDeleteOneOptions<T> options = null
);| Name | Type | Summary |
|---|---|---|
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An object that defines filter criteria using the Data API filter syntax. The method only finds documents that match the filter criteria. Filters can improve performance by reducing the number of documents that the Data API processes. You must use For a list of available filter operators and more examples, see Filter operators for collections (C#). Filters can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in a filter. For an example, see Delete a document that matches a filter. |
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Optional.
Options for this operation.
For more information and examples for general options such as timeout, see Customize API interaction.
For options specific to this method, see Method-specific properties of the |
| Name | Type | Summary |
|---|---|---|
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Optional. Sorts documents by one or more fields, or performs a vector search. You must use For more information, see Sort clauses for collections (C#). Sort clauses can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in sort queries. For vector searches, this parameter can use either |
Examples
The following examples demonstrate how to delete a document in a collection.
Delete a document by ID
All documents have a unique _id property. You can use a filter to find a document with a specific _id, and then delete that document.
The following example uses untyped documents, but you can use strongly-typed classes for compile-time checks and IntelliSense. For more information and examples, see Custom typing for collections.
using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Collections;
using DataStax.AstraDB.DataApi.Core;
namespace Examples;
public class Program
{
static async Task Main()
{
// Get an existing collection
var client = new DataAPIClient();
var database = client.GetDatabase(
"API_ENDPOINT",
"APPLICATION_TOKEN"
);
var collection = database.GetCollection("COLLECTION_NAME");
// Delete a document
var filter = Builders<Document>.CollectionFilter.Eq("_id", "101");
var result = await collection.DeleteOneAsync(filter);
Console.WriteLine(result.DeletedCount);
}
}Delete a document that matches a filter
You can use a filter to find a document that matches specific criteria.
For example, you can find a document with an is_checked_out value of false and a number_of_pages value less than 300.
For a list of available filter operators and more examples, see Filter operators for collections (C#).
Filters can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in a filter.
The following example uses untyped documents, but you can use strongly-typed classes for compile-time checks and IntelliSense. For more information and examples, see Custom typing for collections.
using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Collections;
using DataStax.AstraDB.DataApi.Core;
namespace Examples;
public class Program
{
static async Task Main()
{
// Get an existing collection
var client = new DataAPIClient();
var database = client.GetDatabase(
"API_ENDPOINT",
"APPLICATION_TOKEN"
);
var collection = database.GetCollection("COLLECTION_NAME");
// Delete a document
var filterBuilder = Builders<Document>.CollectionFilter;
var filter = filterBuilder.And(
filterBuilder.Eq("is_checked_out", false),
filterBuilder.Lt("number_of_pages", 300)
);
var result = await collection.DeleteOneAsync(filter);
Console.WriteLine(result.DeletedCount);
}
}Delete a document that is most similar to a search vector
To find the document whose $vector value is most similar to a given vector, use a sort with the vector embeddings that you want to match. For more information, see Find data with vector search.
Vector search is only available for vector-enabled collections.
For more information, see Create a collection that can store vector embeddings and $vector in collections (C#).
The following example uses untyped documents, but you can use strongly-typed classes for compile-time checks and IntelliSense. For more information and examples, see Custom typing for collections.
using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Collections;
using DataStax.AstraDB.DataApi.Core;
namespace Examples;
public class Program
{
static async Task Main()
{
// Get an existing collection
var client = new DataAPIClient();
var database = client.GetDatabase(
"API_ENDPOINT",
"APPLICATION_TOKEN"
);
var collection = database.GetCollection("COLLECTION_NAME");
// Delete a document
var embeddings = new float[] { 0.08f, -0.62f, 0.39f };
var deleteOptions = new CollectionDeleteOneOptions<Document>()
{
Sort = Builders<Document>.CollectionSort.Vector(embeddings),
};
var result = await collection.DeleteOneAsync(null, deleteOptions);
Console.WriteLine(result.DeletedCount);
}
}Delete a document that is most similar to a search string
To find the document whose $vector value is most similar to the $vector value of a given search string, use a sort with the search string that you want to vectorize and match. For more information, see Find data with vector search.
Vector search with vectorize is only available for collections that have vectorize enabled.
For more information, see Create a collection that can automatically generate vector embeddings and $vectorize in collections (C#).
The following example uses untyped documents, but you can use strongly-typed classes for compile-time checks and IntelliSense. For more information and examples, see Custom typing for collections.
using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Collections;
using DataStax.AstraDB.DataApi.Core;
namespace Examples;
public class Program
{
static async Task Main()
{
// Get an existing collection
var client = new DataAPIClient();
var database = client.GetDatabase(
"API_ENDPOINT",
"APPLICATION_TOKEN"
);
var collection = database.GetCollection("COLLECTION_NAME");
// Delete a document
var deleteOptions = new CollectionDeleteOneOptions<Document>()
{
Sort = Builders<Document>.CollectionSort.Vectorize(
"Text to vectorize"
),
};
var result = await collection.DeleteOneAsync(null, deleteOptions);
Console.WriteLine(result.DeletedCount);
}
}Delete a document after applying a non-vector sort
You can use a sort clause to sort documents by one or more fields.
For more information, see Sort clauses for collections (C#).
Sort clauses can use only indexed fields. If you apply selective indexing when you create a collection, you cannot reference non-indexed fields in sort queries.
The following example uses untyped documents, but you can use strongly-typed classes for compile-time checks and IntelliSense. For more information and examples, see Custom typing for collections.
using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Collections;
using DataStax.AstraDB.DataApi.Core;
namespace Examples;
public class Program
{
static async Task Main()
{
// Get an existing collection
var client = new DataAPIClient();
var database = client.GetDatabase(
"API_ENDPOINT",
"APPLICATION_TOKEN"
);
var collection = database.GetCollection("COLLECTION_NAME");
// Delete a document
var filterBuilder = Builders<Document>.CollectionFilter;
var filter = filterBuilder.Eq("metadata.language", "English");
var deleteOptions = new CollectionDeleteOneOptions<Document>()
{
Sort = Builders<Document>
.CollectionSort.Ascending("rating")
.Descending("title"),
};
var result = await collection.DeleteOneAsync(filter, deleteOptions);
Console.WriteLine(result.DeletedCount);
}
}Client reference
For more information, see the client reference.
