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OdbcDataReader.GetOrdinal(String) Method

  • Reference

Definition

Namespace:
System.Data.Odbc
Assembly:
System.Data.Odbc.dll
Assembly:
System.Data.dll
Package:
System.Data.Odbc v8.0.1
Package:
System.Data.Odbc v9.0.0-rc.2.24473.5
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs
Source:
OdbcDataReader.cs

Gets the column ordinal, given the name of the column.

public:
 override int GetOrdinal(System::String ^ value);
public:
 virtual int GetOrdinal(System::String ^ value);
public override int GetOrdinal (string value);
public int GetOrdinal (string value);
override this.GetOrdinal : string -> int
abstract member GetOrdinal : string -> int
override this.GetOrdinal : string -> int
Public Overrides Function GetOrdinal (value As String) As Integer
Public Function GetOrdinal (value As String) As Integer

Parameters

value
String

The name of the column.

Returns

Int32

The zero-based column ordinal.

Implements

GetOrdinal(String)

Examples

The following example demonstrates how to use the 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. The method throws an IndexOutOfRange exception if the zero-based column ordinal is not found.

GetOrdinal is kana-width insensitive.

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

Applies to

See also