OdbcDataReader.GetOrdinal(String) Method

Reference

Definition

Namespace:: System.Data.Odbc

Assembly:: System.Data.Odbc.dll

Assembly:: System.Data.dll

Package:: System.Data.Odbc v10.0.0-preview.1.25080.5

Source:: OdbcDataReader.cs

Source:: OdbcDataReader.cs

Source:: OdbcDataReader.cs

Important

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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

Product	Versions
.NET	8 (package-provided), 9 (package-provided), 10 (package-provided)
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.0 (package-provided)

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