connect sql /insert data

using System;
using System.Data;
using System.Data.SqlClient;

namespace Database_connection_Demo
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello World!");//lucida console
            string connectionString = "server=.;database=sqlconnectiondemo;uid=sa;pwd=886566";
            SqlConnection sqlconnection = new SqlConnection(connectionString);
            sqlconnection.Open();
            //insert new data to db after connecting
            //string sql = "create table dbconnectiondemotable ( StudentID int  identity,StudentName varchar(20) not null, Age int NOT NULL,Gender varchar(8))";
            //SqlCommand command = new SqlCommand(sql, sqlconnection);
            //command.ExecuteNonQuery();
            string sql = "insert into dbconnectiondemotable(StudentName, Age, Gender) values('zhangsan', 33, 'male')";
            SqlCommand command = new SqlCommand(sql, sqlconnection);
            int result =command.ExecuteNonQuery();
            if (result==1)
            {
                Console.WriteLine("insert successfullly!!!");
            }

                                                                                              
        }
    }
}