IDataRecord.GetOrdinal(String) Method

Definition

Namespace:

System.Data

Assembly:

System.Data.Common.dll

Return the index of the named field.

public:
 int GetOrdinal(System::String ^ name);

public int GetOrdinal (string name);

abstract member GetOrdinal : string -> int

Public Function GetOrdinal (name As String) As Integer

Parameters

name

String

The name of the field to find.

Returns

Int32

The index of the named field.

Examples

The following example demonstrates how to use the inherited GetOrdinal method.

public static void ReadData(string connectionString)
{
    string queryString = "SELECT DISTINCT CustomerID FROM Orders";

    using (OdbcConnection connection = new OdbcConnection(connectionString))
    {
        OdbcCommand command = new OdbcCommand(queryString, connection);

        connection.Open();
        OdbcDataReader reader = command.ExecuteReader();

        int customerID = reader.GetOrdinal("CustomerID");

        while (reader.Read())
        {
            Console.WriteLine("CustomerID={0}", reader.GetString(customerID));
        }

        // Call Close when done reading.
        reader.Close();
    }
}

Public Sub ReadData(ByVal connectionString As String)
    Dim queryString As String = "SELECT DISTINCT CustomerID FROM Orders"

    Using connection As New OdbcConnection(connectionString)
        Dim command As New OdbcCommand(queryString, connection)

        connection.Open()

        Dim reader As OdbcDataReader = command.ExecuteReader()

        Dim customerID As Integer = reader.GetOrdinal("CustomerID")

        While reader.Read()
            Console.WriteLine("CustomerID={0}", reader.GetString(customerID))
        End While

        ' Call Close when done reading.
        reader.Close()
    End Using
End Sub

Remarks

GetOrdinal performs a case-sensitive lookup first. If it fails, a second case-insensitive search is made. GetOrdinal is kana-width insensitive. If the index of the named field is not found, an IndexOutOfRangeException is thrown.

Because ordinal-based lookups are more efficient than named lookups, it is inefficient to call GetOrdinal within a loop. Save time by calling GetOrdinal one time and assigning the results to an integer variable for use within the loop.