如何从SQL Server发出ac#console app信号？

using System;
using System.Data.SqlClient;

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            string connectionString = "Data Source=SQLServerInstance;Initial Catalog=DatabaseName;User ID=Username;Password=Password";

            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                try
                {
                    connection.Open();

                    // 执行SQL查询或命令
                    string sqlQuery = "SELECT * FROM TableName";
                    using (SqlCommand command = new SqlCommand(sqlQuery, connection))
                    {
                        SqlDataReader reader = command.ExecuteReader();

                        while (reader.Read())
                        {
                            // 处理查询结果
                            string columnValue = reader.GetString(0);
                            Console.WriteLine(columnValue);
                        }

                        reader.Close();
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine("Error: " + ex.Message);
                }
                finally
                {
                    connection.Close();
                }
            }

            Console.WriteLine("Press any key to exit...");
            Console.ReadKey();
        }
    }
}