Update a row (C#)

Tables with the Data API are currently in public preview. Development is ongoing, and the features and functionality are subject to change. Hyper-Converged Database (HCD), and the use of such, is subject to the DataStax Preview Terms.

Updates a single row in a table.

If the row does not already exist and the update includes at least one non-null or non-empty value, creates a new row.

For general information about working with tables and rows, see About tables with the Data API (C#).

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

Updates the specified row.

If no row matches the specified primary key and the update includes at least one non-null or non-empty value, then a new row is created with the specified $set values and primary key values. Any omitted or $unset columns are set to null in the new row.

Does not return anything.

A rare edge case, related to underlying Apache Cassandra® functionality, can cause a row to disappear altogether when all of its columns are set to null.

This happens if the row was previously created from an update operation that had no pre-existing row to modify.

Parameters

Use the UpdateOneAsync method, which belongs to the Table class. You can also use UpdateOne, which is the synchronous version of the method.

Method signature

public Task UpdateOneAsync(
  TableFilter<T> filter,
  UpdateBuilder<T> update,
  TableUpdateOneOptions<T> options = null
);

Name Type Summary

Name	Type	Summary
`filter`	`TableFilter`	Describes the full primary key of the row to update. For this method, the filter can only use the `$eq` operator and columns in the primary key.
`update`	`UpdateBuilder`	Defines the update using Data API operators. For a list of available operators and more examples, see Update operators for tables (C#). You cannot update primary key values. If you need to modify a row’s primary key, delete the row and then insert a new row with the desired primary key values.
`options`	`TableUpdateOneOptions`	Optional. General API options for this operation, including the timeout. For more information and examples, see Customize API interaction.

filter

TableFilter

Describes the full primary key of the row to update.

For this method, the filter can only use the $eq operator and columns in the primary key.

update

UpdateBuilder

Defines the update using Data API operators.

For a list of available operators and more examples, see Update operators for tables (C#).

You cannot update primary key values. If you need to modify a row’s primary key, delete the row and then insert a new row with the desired primary key values.

options

TableUpdateOneOptions

Optional. General API options for this operation, including the timeout. For more information and examples, see Customize API interaction.

Examples

The following examples demonstrate how to update a row in a table.

Update multiple columns

You can combine multiple operators and properties in a single call. For the full list of operators, see Update operators for tables (C#).

If the row does not already exist and the update includes at least one non-null or non-empty value, creates a new row.

Typed
Untyped

You can manually define a client-side type for your table to help statically catch errors. For more information and examples, see Custom typing for tables.

using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Core;
using DataStax.AstraDB.DataApi.Core.Query;
using DataStax.AstraDB.DataApi.Tables;

namespace Examples;

public class Book
{
  [ColumnPrimaryKey(1)]
  [ColumnName("title")]
  public string Title { get; set; } = null!;

  [ColumnPrimaryKey(2)]
  [ColumnName("author")]
  public string Author { get; set; } = null!;

  [ColumnName("rating")]
  public float? Rating { get; set; }

  [ColumnName("genres")]
  public HashSet<string>? Genres { get; set; }

  [ColumnName("borrower")]
  public string? Borrower { get; set; }
}

public class Program
{
  static async Task Main()
  {
    // Get an existing table
    var client = new DataAPIClient(
      new CommandOptions() { Destination = DataAPIDestination.HCD }
    );

    var database = client.GetDatabase(
      "API_ENDPOINT",
      DataAPIClient.UsernamePasswordTokenProvider(
        "USERNAME",
        "PASSWORD"
      ),
      "KEYSPACE_NAME"
    );

    var table = database.GetTable<Book>("TABLE_NAME");

    // Update a row
    var filterBuilder = Builders<Book>.TableFilter;
    var filter = filterBuilder.And(
      filterBuilder.Eq(b => b.Title, "Hidden Shadows of the Past"),
      filterBuilder.Eq(b => b.Author, "John Anthony")
    );

    var update = Builders<Book>
      .TableUpdate.Set(x => x.Rating, 4.5f)
      .Set(x => x.Genres, new HashSet<string> { "Fiction", "Drama" })
      .Unset(x => x.Borrower);

    await table.UpdateOneAsync(filter, update);
  }
}

If you don’t pass a type parameter, the collection or table remains untyped. This is a more flexible but less type-safe option.

using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Core;
using DataStax.AstraDB.DataApi.Tables;

namespace Examples;

public class Program
{
  static async Task Main()
  {
    // Get an existing table
    var client = new DataAPIClient(
      new CommandOptions() { Destination = DataAPIDestination.HCD }
    );

    var database = client.GetDatabase(
      "API_ENDPOINT",
      DataAPIClient.UsernamePasswordTokenProvider(
        "USERNAME",
        "PASSWORD"
      ),
      "KEYSPACE_NAME"
    );

    var table = database.GetTable("TABLE_NAME");

    // Update a row
    var filterBuilder = Builders<Row>.TableFilter;
    var filter = filterBuilder.And(
      filterBuilder.Eq("title", "Hidden Shadows of the Past"),
      filterBuilder.Eq("author", "John Anthony")
    );

    var update = Builders<Row>
      .TableUpdate.Set("rating", 4.5)
      .Set("genres", new HashSet<string> { "Fiction", "Drama" })
      .Unset("borrower");

    await table.UpdateOneAsync(filter, update);
  }
}

Unset columns

To unset a column, you can use the $unset operator, or you can use the $set operator and an empty value. Either operation will delete the value in the specified column.

Unsetting a column produces a tombstone. Excessive tombstones can impact query performance.

Typed
Untyped

You can manually define a client-side type for your table to help statically catch errors. For more information and examples, see Custom typing for tables.

using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Core;
using DataStax.AstraDB.DataApi.Core.Query;
using DataStax.AstraDB.DataApi.Tables;

namespace Examples;

public class Book
{
  [ColumnPrimaryKey(1)]
  [ColumnName("title")]
  public string Title { get; set; } = null!;

  [ColumnPrimaryKey(2)]
  [ColumnName("author")]
  public string Author { get; set; } = null!;

  [ColumnName("number_of_pages")]
  public int? NumberOfPages { get; set; }

  [ColumnName("genres")]
  public HashSet<string>? Genres { get; set; }

  [ColumnName("due_date")]
  public DateOnly? DueDate { get; set; }
}

public class Program
{
  static async Task Main()
  {
    // Get an existing table
    var client = new DataAPIClient(
      new CommandOptions() { Destination = DataAPIDestination.HCD }
    );

    var database = client.GetDatabase(
      "API_ENDPOINT",
      DataAPIClient.UsernamePasswordTokenProvider(
        "USERNAME",
        "PASSWORD"
      ),
      "KEYSPACE_NAME"
    );

    var table = database.GetTable<Book>("TABLE_NAME");

    // Update a row
    var filterBuilder = Builders<Book>.TableFilter;
    var filter = filterBuilder.And(
      filterBuilder.Eq(b => b.Title, "Hidden Shadows of the Past"),
      filterBuilder.Eq(b => b.Author, "John Anthony")
    );

    var update = Builders<Book>.TableUpdate.Unset(x => x.Genres);

    await table.UpdateOneAsync(filter, update);
  }
}

If you don’t pass a type parameter, the collection or table remains untyped. This is a more flexible but less type-safe option.

using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Core;
using DataStax.AstraDB.DataApi.Tables;

namespace Examples;

public class Program
{
  static async Task Main()
  {
    // Get an existing table
    var client = new DataAPIClient(
      new CommandOptions() { Destination = DataAPIDestination.HCD }
    );

    var database = client.GetDatabase(
      "API_ENDPOINT",
      DataAPIClient.UsernamePasswordTokenProvider(
        "USERNAME",
        "PASSWORD"
      ),
      "KEYSPACE_NAME"
    );

    var table = database.GetTable("TABLE_NAME");

    // Update a row
    var filterBuilder = Builders<Row>.TableFilter;
    var filter = filterBuilder.And(
      filterBuilder.Eq("title", "Hidden Shadows of the Past"),
      filterBuilder.Eq("author", "John Anthony")
    );

    var update = Builders<Row>.TableUpdate.Unset("genres");

    await table.UpdateOneAsync(filter, update);
  }
}

Client reference

For more information, see the client reference.

Update a row (C#)

Result

Parameters

Examples

Update multiple columns

Unset columns

Client reference

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