You can access the same column information about the results of a query that you can for table schemas. See Columns for the columns returned.

Retrieving Result Set Metadata

You can use the GetSchemaTable method of the AmazonDynamoDBDataReader to retrieve result set metadata. Call GetSchemaTable after calling ExecuteReader.

Each row of the DataTable describes a column in the query's result.

C#

string connectionString = "AWS Access Key=xxx;AWS Secret Key=xxx;Domain=amazonaws.com;AWS Region=OREGON;";

using (AmazonDynamoDBConnection conn = new AmazonDynamoDBConnection(connectionString)) {
  AmazonDynamoDBCommand cmd = new AmazonDynamoDBCommand("SELECT * FROM Account WHERE FirstName <> 'Bob'", conn);
  AmazonDynamoDBDataReader rdr = cmd.ExecuteReader();
  DataTable schemaTable = rdr.GetSchemaTable();
  foreach (DataRow row in schemaTable.Rows) {
    foreach (DataColumn col in schemaTable.Columns) {
      Console.WriteLine("{0}: {1}", col.ColumnName, row[col]);
    }
  }
}

VB.NET

Dim connectionString As String = "AWS Access Key=xxx;AWS Secret Key=xxx;Domain=amazonaws.com;AWS Region=OREGON;"

Using conn As New AmazonDynamoDBConnection(connectionString)
  Dim cmd As New AmazonDynamoDBCommand("SELECT * FROM Account WHERE FirstName <> 'Bob'", conn)
  Dim rdr As AmazonDynamoDBDataReader = cmd.ExecuteReader()
  Dim schemaTable As DataTable = rdr.GetSchemaTable()
  For Each row As DataRow In schemaTable.Rows
    For Each col As DataColumn In schemaTable.Columns
      Console.WriteLine("{0}: {1}", col.ColumnName, row(col))
    Next
  Next
End Using