ADO.NET Provider for Cassandra

Build 23.0.8839

Querying with the DataAdapter

The CData ADO.NET Provider for Cassandra implements two ADO.NET interfaces you can use to retrieve data from Cassandra: CassandraDataAdapter and CassandraDataReader objects. Whereas CassandraDataAdapter objects retrieve a single result set of all the data that matches a query, CassandraDataReader objects fetch data in subset increments as needed.

Using the CassandraDataAdapter

Use the adapter's Fill method to retrieve data from the data source. An empty DataTable instance is passed as an argument to the Fill method. When the method returns, the DataTable instance is populated with the queried data. Note that the CassandraDataAdapter is slower than the CassandraDataReader because the Fill method needs to retrieve all data from the data source before returning.

The following example selects the Id and Name columns of the Products table:

C#

string connectionString = "Database=MyCassandraDB;Port=9042;Server=127.0.0.1;";

using (CassandraConnection connection = new CassandraConnection(connectionString)) {
  CassandraDataAdapter dataAdapter = new CassandraDataAdapter(
  "SELECT Id, Name FROM \"CData\".\"Sample\".Products", connection);

  DataTable table = new DataTable();
  dataAdapter.Fill(table);

  Console.WriteLine("Contents of Products.");

  foreach (DataRow row in table.Rows) {
    Console.WriteLine("{0}: {1}", row["Id"], row["Name"]);
  }
}

VB.NET

Dim connectionString As String = "Database=MyCassandraDB;Port=9042;Server=127.0.0.1;"

Using connection As New CassandraConnection(connectionString)
  Dim dataAdapter As New CassandraDataAdapter("SELECT Id, Name FROM \"CData\".\"Sample\".Products", connection)

  Dim table As New DataTable()
  dataAdapter.Fill(table)

  Console.WriteLine("Contents of Products.")

  For Each row As DataRow In table.Rows
    Console.WriteLine("{0}: {1}", row("Id"), row("Name"))
  Next
End Using

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Build 23.0.8839