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SqlDataReader.GetOrdinal Method

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

Namespace:  System.Data.SqlClient
Assembly:  System.Data (in System.Data.dll)

public override int GetOrdinal(
	string name
)

Parameters

name
Type: System.String

The name of the column.

Return Value

Type: System.Int32
The zero-based column ordinal.

Implements

IDataRecord.GetOrdinal(String)

ExceptionCondition
IndexOutOfRangeException

The name specified is not a valid column name.

GetOrdinal performs a case-sensitive lookup first. If it fails, a second, case-insensitive search occurs (a case-insensitive comparison is done using the database collation). Unexpected results can occur when comparisons are affected by culture-specific casing rules. For example, in Turkish, the following example yields the wrong results because the file system in Turkish does not use linguistic casing rules for the letter 'i' in "file". 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 once and assigning the results to an integer variable for use within the loop.

The following example demonstrates how to use the GetOrdinal method.

private static void ReadGetOrdinal(string connectionString)
{
    string queryString = "SELECT DISTINCT CustomerID FROM dbo.Orders;";
    using (SqlConnection connection =
               new SqlConnection(connectionString))
    {
        SqlCommand command =
            new SqlCommand(queryString, connection);
        connection.Open();

        SqlDataReader reader = command.ExecuteReader();

        // Call GetOrdinal and assign value to variable. 
        int customerID = reader.GetOrdinal("CustomerID");

        // Use variable with GetString inside of loop. 
        while (reader.Read())
        {
            Console.WriteLine("CustomerID={0}", reader.GetString(customerID));
        }

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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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