使用ADO.NET和AddWithValue()处理空值

using System;
using System.Data.SqlClient;

namespace ADO.NET_AddWithValue
{
    class Program
    {
        static void Main(string[] args)
        {
            string connectionString = "Data Source=localhost;Initial Catalog=myDatabase;Integrated Security=True";
            string sql = "INSERT INTO myTable (name, age) VALUES (@name, @age)";

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                SqlCommand command = new SqlCommand(sql, connection);
                command.Parameters.AddWithValue("@name", "John");
                command.Parameters.AddWithValue("@age", DBNull.Value);

                connection.Open();
                command.ExecuteNonQuery();
            }
        }
    }
}