SQL命令c#中的查询字符串

using System;
using System.Data.SqlClient;

class Program
{
    static void Main()
    {
        string connectionString = "Server=myServerAddress;Database=myDatabase;User Id=myUsername;Password=myPassword;";
        string queryString = "SELECT * FROM myTable";

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            SqlCommand command = new SqlCommand(queryString, connection);
            connection.Open();

            using (SqlDataReader reader = command.ExecuteReader())
            {
                while (reader.Read())
                {
                    Console.WriteLine(reader["columnName"]);
                }
            }
        }
    }
}