Update operators for tables (C#)

Some Data API commands, like Update a row (C#), use update operators to modify rows in a table.

Set

The $set operator sets the value of the specified column to the specified value.

  • Typed

  • Untyped

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

using DataStax.AstraDB.DataApi;
using DataStax.AstraDB.DataApi.Core;
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 double? Rating { get; set; }

  [ColumnName("genres")]
  public List<string>? Genres { 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");

    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(b => b.Rating, 4.5)
      .Set(b => b.Genres, new List<string> { "Fiction", "Drama" });

    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");

    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[] { "Fiction", "Drama" });

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

Unset

The $unset operator sets the specified column’s value to null or the equivalent empty form, such as [] or {} for map, list, and set types.

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

  • Typed

  • Untyped

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

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);
  }
}

Combine operators

You can use multiple update operators in a single update.

  • Typed

  • Untyped

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

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);
  }
}

Unsupported operators

  • $rename isn’t supported. Instead, use alterTable to add and drop columns.

  • $currentDate isn’t supported.

  • The array operators $push, $each, $pullAll, $addToSet, $pop, and $position aren’t supported.

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