SqlDataReade.GetOrdinal() 方法

SqlDataReade.GetOrdinal() 方法 :在给定列名称的情况下获取列序号。

        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();
            }
        }