The CData ADO.NET Provider for Cassandra enables you to take advantage of the bulk load support in Cassandra through CassandraDataAdapters. You can use the Batch API to execute related SQL data manipulation statements simultaneously. The provider translates all SQL queries in the batch into a single request.

Using the ADO.NET Batch API

Performing a batch update consists of the following basic steps:

1. Define custom parameterized SQL statements in CassandraCommand objects.
2. Set the UpdatedRowSource property of the CassandraCommand object to "UpdateRowSource.None".
3. Assign the CassandraCommand objects to the CassandraDataAdapter.
4. Add the parameters to the command.
5. Call the CassandraDataAdapter's Update method. Pass in a DataSet or DataTable containing your changes.

Controlling Batch Size

Depending on factors such as the size of the request, your network resources, and the performance of the server, you may gain performance by executing several smaller batch requests. You can control the size of each batch by setting the CassandraDataAdapter's UpdateBatchSize property to a positive integer.

Bulk INSERT

The following code prepares a single batch that inserts records in bulk. The example executes a batch INSERT of new DataRows, which have the "Added" state.

C#

CassandraDataAdapter adapter = new CassandraDataAdapter();

using (CassandraConnection conn = new CassandraConnection("Database=MyCassandraDB;Port=9042;Server=127.0.0.1;")) {
  conn.Open();
  adapter.InsertCommand = conn.CreateCommand();
  adapter.InsertCommand.CommandText = "INSERT INTO \"CData\".\"Sample\".Products (Name) VALUES (@Name)";
  adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None;
  adapter.InsertCommand.Parameters.Add("@Name", "Name");

  DataTable batchDataTable = new DataTable();
  batchDataTable.Columns.Add("Name", typeof(string));
  batchDataTable.Rows.Add("Jon Doe");
  batchDataTable.Rows.Add("John");
  adapter.UpdateBatchSize = 2;
  adapter.Update(batchDataTable);
}

VB.NET

 
Dim adapter As New CassandraDataAdapter()

Using conn As New CassandraConnection("Database=MyCassandraDB;Port=9042;Server=127.0.0.1;")
  conn.Open()
  adapter.InsertCommand = conn.CreateCommand()
  adapter.InsertCommand.CommandText = "INSERT INTO \"CData\".\"Sample\".Products (Id) VALUES (@Name)"
  adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None
  adapter.InsertCommand.Parameters.Add("@Name", "Name")

  Dim batchDataTable As New DataTable()
  batchDataTable.Columns.Add("Name", GetType(String))
  batchDataTable.Rows.Add("John")
  batchDataTable.Rows.Add("Jon Doe")
  adapter.UpdateBatchSize = 2
  adapter.Update(batchDataTable)
End Using

Bulk Update

A batch update additionally requires the primary key of each row to update. The following example executes a batch for all DataRow records with a "Modified" state:

C#

CassandraDataAdapter adapter = new CassandraDataAdapter();

using (CassandraConnection conn = new CassandraConnection("Database=MyCassandraDB;Port=9042;Server=127.0.0.1;")) { 
  conn.Open();
  adapter.UpdateCommand = conn.CreateCommand();
  adapter.UpdateCommand.CommandText = "UPDATE \"CData\".\"Sample\".Products SET Name=@Name WHERE Id=@Id";
  adapter.UpdateCommand.Parameters.Add("@Name", "Name");
  adapter.UpdateCommand.Parameters.Add("@Id", "Id");
  adapter.UpdateCommand.UpdatedRowSource = UpdateRowSource.None; 
  DataTable batchDataTable = new DataTable();
  batchDataTable.Columns.Add("Name", typeof(string));
  batchDataTable.Rows.Add("Jon Doe");
  batchDataTable.Rows.Add("John");
  adapter.UpdateBatchSize = 2;
  adapter.Update(dataTable);
}

VB.NET

 
Dim adapter As New CassandraDataAdapter()

Using conn As New CassandraConnection("Database=MyCassandraDB;Port=9042;Server=127.0.0.1;")
  conn.Open()
  adapter.UpdateCommand = conn.CreateCommand()
  adapter.UpdateCommand.CommandText = "UPDATE \"CData\".\"Sample\".Products SET Name=@Name WHERE Id=@Id"
  adapter.UpdateCommand.Parameters.Add("@Name", "Name")
  adapter.UpdateCommand.Parameters.Add("@Id", "Id")
  adapter.UpdateCommand.UpdatedRowSource = UpdateRowSource.None
  Dim batchDataTable As New DataTable()
  batchDataTable.Columns.Add("Name", GetType(String))
  batchDataTable.Rows.Add("John")
  batchDataTable.Rows.Add("Jon Doe")
  adapter.UpdateBatchSize = 2
  adapter.Update(dataTable)
End Using

Bulk Delete

The following code prepares a single batch that deletes records in bulk. The primary key for each row is required. The following example executes a batch for all DataRow records with a "Deleted" state:

C#

CassandraDataAdapter adapter = new CassandraDataAdapter();

using (CassandraConnection conn = new CassandraConnection("Database=MyCassandraDB;Port=9042;Server=127.0.0.1;")) {
  conn.Open();
  adapter.DeleteCommand = conn.CreateCommand();
  adapter.DeleteCommand.CommandText = "DELETE FROM \"CData\".\"Sample\".Products WHERE Id=@Id";
  adapter.DeleteCommand.Parameters.Add("@Id", "Id");
  adapter.DeleteCommand.UpdatedRowSource = UpdateRowSource.None; 
  adapter.UpdateBatchSize = 2;
  adpater.Update(table);
}

VB.NET

Dim adapter As New CassandraDataAdapter()

Using conn As New CassandraConnection("Database=MyCassandraDB;Port=9042;Server=127.0.0.1;")
  conn.Open()
  adapter.DeleteCommand = conn.CreateCommand()
  adapter.DeleteCommand.CommandText = "DELETE FROM \"CData\".\"Sample\".Products WHERE Id=@Id"
  adapter.DeleteCommand.Parameters.Add("@Id", "Id")
  adapter.DeleteCommand.UpdatedRowSource = UpdateRowSource.None 
  adapter.UpdateBatchSize = 2
  adpater.Update(table)
End Using