如何使用C#在数据库中写入空值

using System;
using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connectionString = "YourConnectionStringHere";
        string sql = "INSERT INTO YourTable (Column1, Column2) VALUES (@Column1, @Column2)";

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            SqlCommand command = new SqlCommand(sql, connection);
            command.Parameters.AddWithValue("@Column1", "SomeValue");
            command.Parameters.AddWithValue("@Column2", DBNull.Value); // 使用DBNull.Value表示空值

            try
            {
                connection.Open();
                int rowsAffected = command.ExecuteNonQuery();
                Console.WriteLine("Rows affected: " + rowsAffected);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error: " + ex.Message);
            }
        }
    }
}