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OleDbDataReader.GetOrdinal(String) Method

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Definition

Namespace:
System.Data.OleDb
Assembly:
System.Data.OleDb.dll
Assembly:
System.Data.dll
Package:
System.Data.OleDb v9.0.0
Source:
OleDbDataReader.cs
Source:
OleDbDataReader.cs
Source:
OleDbDataReader.cs

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

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

Parameters

name
String

The name of the column.

Returns

Int32

The zero-based column ordinal.

Implements

GetOrdinal(String)

Exceptions

IndexOutOfRangeException

The name specified is not a valid column name.

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 (OleDbConnection connection = new OleDbConnection(connectionString))
    {
        OleDbCommand command = new OleDbCommand(queryString, connection);

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

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

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

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

    Using connection As New OleDbConnection(connectionString)
        Dim command As New OleDbCommand(queryString, connection)

        connection.Open()

        Dim reader As OleDbDataReader = command.ExecuteReader()

        Dim customerID As Integer = reader.GetOrdinal("CustomerID")
        While reader.Read()
            Console.WriteLine("CustomerID={0}", reader.GetString(customerID))
        End While
        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. Save time by calling GetOrdinal one time and assigning the results to an integer variable for use within the loop.

Applies to

See also