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

Using the OracleOciDataAdapter

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

The following example selects the CompanyName and City columns of the Customers table:

C#

string connectionString = "User=scott;Password=tiger;Server=127.0.0.1;Port=1521;";

using (OracleOciConnection connection = new OracleOciConnection(connectionString)) {
  OracleOciDataAdapter dataAdapter = new OracleOciDataAdapter(
  "SELECT CompanyName, City FROM \"CData\".\"SYSTEM\".Customers", connection);

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

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

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

VB.NET

Dim connectionString As String = "User=scott;Password=tiger;Server=127.0.0.1;Port=1521;"

Using connection As New OracleOciConnection(connectionString)
  Dim dataAdapter As New OracleOciDataAdapter("SELECT CompanyName, City FROM \"CData\".\"SYSTEM\".Customers", connection)

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

  Console.WriteLine("Contents of Customers.")

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