The following section shows how to execute commands using ADO.NET base classes like DbCommand and DbDataAdapter.

Executing Commands to Apache Impala

The following code executes a "SELECT *" query to Apache Impala, given an existing DbConnection object.

using (connection) {

  // Create the DbCommand.
  DbCommand command = factory.CreateCommand();
  command.CommandText = 
    "SELECT * FROM [CData].[Default].Customers";

  command.Connection = connection;

  // Create the DbDataAdapter.
  DbDataAdapter adapter = factory.CreateDataAdapter();
  adapter.SelectCommand = command;

  // Fill the DataTable.
  DataTable table = new DataTable();
  adapter.Fill(table);

  //  Display each row and column value.
  foreach (DataRow row in table.Rows) {
    foreach (DataColumn column in table.Columns) {
      Console.WriteLine(row[column]);
    }
  }
}