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

Using the GoogleBigQueryDataAdapter

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 GoogleBigQueryDataAdapter is slower than the GoogleBigQueryDataReader because the Fill method needs to retrieve all data from the data source before returning.

The following example selects the actor.attributes.email and repository.name columns of the github_nested table:

C#

string connectionString = "InitiateOAuth=GETANDREFRESH;ProjectId=NameOfProject;DatasetId=NameOfDataset;";

using (GoogleBigQueryConnection connection = new GoogleBigQueryConnection(connectionString)) {
  GoogleBigQueryDataAdapter dataAdapter = new GoogleBigQueryDataAdapter(
  "SELECT actor.attributes.email, repository.name FROM [publicdata].[samples].github_nested", connection);

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

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

  foreach (DataRow row in table.Rows) {
    Console.WriteLine("{0}: {1}", row["actor.attributes.email"], row["repository.name"]);
  }
}

VB.NET

Dim connectionString As String = "InitiateOAuth=GETANDREFRESH;ProjectId=NameOfProject;DatasetId=NameOfDataset;"

Using connection As New GoogleBigQueryConnection(connectionString)
  Dim dataAdapter As New GoogleBigQueryDataAdapter("SELECT actor.attributes.email, repository.name FROM [publicdata].[samples].github_nested", connection)

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

  Console.WriteLine("Contents of github_nested.")

  For Each row As DataRow In table.Rows
    Console.WriteLine("{0}: {1}", row("actor.attributes.email"), row("repository.name"))
  Next
End Using